Qwt、QChart、QCustomPlot使用及对比

https://blog.csdn.net/qq_43627907/article/details/109661525

Qwt、QChart、QCustomPlot使用🕐 🕜 🕙 🕥 🕚 🕦 😄 😆

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文章目录

• Qwt、QChart、QCustomPlot使用🕐 🕜 🕙 🕥 🕚 🕦 😄 😆
• • @[toc]
  • 效果图
  • 比较
• Qwt
• • 1、下载源码
  • 2、将Qwt编译成共享库
  • 3、添加Qwt
  • 4、使用Qwt
  • 5、添加帮助文档
  • 6、示例
• QCustomPlot
• • 1、下载源码
  • 2、使用源码
  • 3、将QCustomPlot编译成共享库
  • 4、示例
• QChart
• • 1、安装
  • 2、示例

效果图

• Qwt

• Qcustomplot

• QChart

比较

• 美观方面：

  • Qcustomplot≈Qchart > Qwt
  • Qcustomplot界面简洁大方；
  • Qchart界面华丽优美，其中QChart中绘制的线条处不能使用鼠标，所以在数据量大的时候会引响鼠标的缩放、移动图表操作；
  • Qwt界面老旧，在美观上不如Qcustomplot和Qchart ，并且在使用鼠标移动图表时会产生空白区域。

• 性能方面：

  • 绘制数据性能：Qchart>Qcustomplot > Qwt

  • 绘制数据数量：Qcustomplot >Qchart> Qwt

  • 绘制1000个数据点时，qcustomplot平均耗时 13.6毫秒，Qwt平均耗时40毫秒，QChart平均耗时12.5毫秒;

    绘制10000个数据点时，qcustomplot平均耗时 21.6毫秒，Qwt平均耗时78毫秒，QChart平均耗时13.5毫秒;

    绘制100000个数据点时，qcustomplot平均耗时22.5毫秒，Qwt平均耗时524毫秒，QChart平均耗时20.7毫秒；

    绘制500000个数据点时，qcustomplot平均耗时43.3毫秒，QChart平均耗时194.25毫秒。

• 功能方面：

  • QChart、Qwt功能比较齐全，并且可绘制图表种类多；
  • qcustomplot在图表种类上、常用功能上较少。

• 使用方面：

  • QChart无需配置，主要在安装Qt时勾选就可以，在程序编写时上手较慢，许多功能需要重写；
  • Qwt安装配置比较复杂；
  • QCustomPlot体积小、简单易用，上手快，并且QCustomPlot只有两个源文件，可直接添加进工程，更容易直接修改源码。

Qwt

1、下载源码

• 下载地址
• 选择下载最新版本。

• 进入6.1.5后会有四个文件，前两个是Qwt源码，区别就是压缩格式，后两个为帮助文档。

2、将Qwt编译成共享库

• 将下载的源码解压后使用Qt打开。

  

  

  

• 使用Release构建项目。

  

  

• 等待一段时间后就可以在qwt-6.1.5同级目录下生成build-qwt-Desktop_Qt_5_14_2_MinGW_64_bit-Release。

3、添加Qwt

• 进入build-qwt-Desktop_Qt_5_14_2_MinGW_64_bit-Release。

  

• 进入lib目录，将qwt.dll、qwtd.dll复制到Qt安装目录D:\Qt\Qt5.14.2\5.14.2\mingw73_64\bin，注意之前使用的是MinGW64编译的，就将qwt.dll、qwtd.dll复制到mingw73_64(有的不是73)的bin下。

• 将libqwt.a、libqwtd.a（使用MSVC编译的是libqwt.lib）复制到D:\Qt\Qt5.14.2\5.14.2\mingw73_64\lib目录下

  

• 进入build-qwt-Desktop_Qt_5_14_2_MinGW_64_bit-Release**\designer\plugins\designer目录，将libqwt_designer_plugin.a和qwt_designer_plugin.dll复制到Qt安装目录 D:\Qt\Qt5.14.2\5.14.2\mingw73_64\plugins\designer**下。

• 将解压的qwt-6.1.5文件夹下的src文件夹复制到D:\Qt\Qt5.14.2\5.14.2**\mingw73_64\include**目录下，将src重命名为Qwt。

4、使用Qwt

• 打开Qt，新建一个项目，使用MinGw64。

  

• 双击进入ui文件，选择Frame控件 –> 右键提升为QwtPlot。

  

• 或者右键点击UI文件 –> 用…打开 –> Qt Designer（高版本Qt直接双击打开ui文件是无法加载Qwt的）。

  

• 就会出现Qwt控件栏。

  

• 将Qwt控件拖进Winget中，然后保存，这时直接编译会报错。

  

• 鼠标右键点击工程名，选择添加库。

  

  

• 点击库文件浏览。

  

• 选择之前复制的Qt安装路径D:\Qt\Qt5.14.2\5.14.2**\mingw73_64\lib**下的libqwt.a，点击下一步。

  

• 会在 .pro文件中生成。

  

• 将INCLUDEPATH和DEPENDPATH改为之前复制的Qwt文件路径，或者在添加头文件时添加#include <Qwt/qwt_*.h>。

  

• 然后编译运行就可以成功了。

  

5、添加帮助文档

• 用户指南

• 打开Qt –> 工具 –> 选项。

  

• 选择帮助 –> 添加 –> 找到下载的qwt-6.1.5.qch文件 –> OK。

  

  

• 通过帮助 –> 索引 就可以找到添加的Qwt文档。

  

6、示例

• 进入ui文件，选择Frame控件，提升为QwtPlot，重命名为m_plot，添加控件PushButton。

  

• MainWidget.h文件源码。

  public:
      MainWindow(QWidget *parent = nullptr);
      ~MainWindow();
  QTimer <span class="token operator">*</span>m_timer<span class="token punctuation">;</span>                              <span class="token comment">//定时器</span>
  QwtPlotCurve <span class="token operator">*</span>m_curvep<span class="token punctuation">;</span>                       <span class="token comment">//绘图项-曲线</span>
  QwtPlotGrid <span class="token operator">*</span>m_gridp<span class="token punctuation">;</span>                         <span class="token comment">//网格部件</span>
  
  private slots:
  
  void on_pushButton_clicked();                 //暂停定时器
  
  void mouseReleaseEvent(QMouseEvent * event);  //鼠标释放事件
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• MainWidget.cpp文件源码。

  #include "mainwindow.h"
  #include "ui_mainwindow.h"
  #include <qwt_plot_grid.h>
  #include <qwt_legend.h>
  #include <qwt_plot_curve.h>
  #include <qwt_symbol.h>
  #include <qwt_plot.h>
  #include <QVBoxLayout>
  #include <QPushButton>
  #include <QTimer>
  #include <QRandomGenerator>
  #include <QDateTime>
  #include <qwt_plot_zoomer.h>
  #include <qwt_plot_panner.h>
  #include <qwt_plot_magnifier.h>
  #include <qwt_plot_canvas.h>
  #include <QToolTip>
  #include <qwt_painter.h>
  MainWindow::MainWindow(QWidget *parent)
  
  : QMainWindow(parent)
  
  , ui(new Ui::MainWindow)
  
  {
  
  ui->setupUi(this);
  ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setTitle</span><span class="token punctuation">(</span><span class="token string">"标题"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                    <span class="token comment">//设置图的标题</span>
  ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setCanvasBackground</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>white<span class="token punctuation">)</span><span class="token punctuation">;</span>                                     <span class="token comment">//设置图纸的背景颜色</span>
  ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setAxisScale</span><span class="token punctuation">(</span>QwtPlot<span class="token operator">::</span>yLeft<span class="token punctuation">,</span> <span class="token number">0.0</span><span class="token punctuation">,</span> <span class="token number">1000.0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                          <span class="token comment">//设置y轴范围</span>
  ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setAxisScale</span><span class="token punctuation">(</span>QwtPlot<span class="token operator">::</span>xBottom<span class="token punctuation">,</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">50</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                               <span class="token comment">//设置x轴范围</span>
  ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">insertLegend</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token function">QwtLegend</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                      <span class="token comment">//创建一个图例</span>
  ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setAxisTitle</span><span class="token punctuation">(</span>QwtPlot<span class="token operator">::</span>xBottom<span class="token punctuation">,</span> <span class="token string">"x轴"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                              <span class="token comment">//设置横坐标标题</span>
  ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setAxisTitle</span><span class="token punctuation">(</span>QwtPlot<span class="token operator">::</span>yLeft<span class="token punctuation">,</span> <span class="token string">"y轴"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                <span class="token comment">//设置纵坐标标题</span>
  <span class="token comment">//l_plot-&gt;setAutoReplot(true);                                                  //设置自动重绘，不建议使用</span>
  
  m_gridp <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token function">QwtPlotGrid</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  m_gridp<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">attach</span><span class="token punctuation">(</span>ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token punctuation">)</span><span class="token punctuation">;</span>                                                     <span class="token comment">//添加网格</span>
  
  <span class="token comment">//声明一个曲线，并设置相关属性</span>
  m_curvep <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token function">QwtPlotCurve</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  m_curvep<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setTitle</span><span class="token punctuation">(</span><span class="token string">"数据1"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                   <span class="token comment">//设置曲线名字，该名字会被作为图例的标识</span>
  m_curvep<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setPen</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>blue<span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                <span class="token comment">//设置画笔的颜色为blue,线宽为2像素</span>
  m_curvep<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setRenderHint</span><span class="token punctuation">(</span>QwtPlotItem<span class="token operator">::</span>RenderAntialiased<span class="token punctuation">,</span> <span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                <span class="token comment">//渲染抗锯齿</span>
  m_curvep<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">attach</span><span class="token punctuation">(</span>ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token punctuation">)</span><span class="token punctuation">;</span>                                                 <span class="token comment">//将曲线绘制到画布上</span>
  
  <span class="token comment">//声明并设置一个在画布上的符号`</span>
  QwtSymbol <span class="token operator">*</span>symbol <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token function">QwtSymbol</span><span class="token punctuation">(</span>QwtSymbol<span class="token operator">::</span>Ellipse<span class="token punctuation">,</span>
      <span class="token function">QBrush</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>yellow<span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token function">QPen</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>red<span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token function">QSize</span><span class="token punctuation">(</span><span class="token number">8</span><span class="token punctuation">,</span> <span class="token number">8</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                       <span class="token comment">//在线上绘制端点</span>
  
  // curve->setSymbol( symbol );                                                 //添加到线上
  QwtPlotZoomer <span class="token operator">*</span>zoomer <span class="token operator">=</span> <span class="token keyword">new</span>  <span class="token function">QwtPlotZoomer</span><span class="token punctuation">(</span>ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">canvas</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>             <span class="token comment">//鼠标选择图形局部放大</span>
  zoomer<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setMousePattern</span><span class="token punctuation">(</span> QwtEventPattern<span class="token operator">::</span>MouseSelect1<span class="token punctuation">,</span> Qt<span class="token operator">::</span>RightButton<span class="token punctuation">,</span> Qt<span class="token operator">::</span>ControlModifier <span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token comment">//ctrl+右键 放大 右键恢复原样</span>
  
  QwtPlotMagnifier <span class="token operator">*</span>magnifier <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token function">QwtPlotMagnifier</span><span class="token punctuation">(</span>ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">canvas</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>     <span class="token comment">//默认的滑轮及右键缩放功能  图形的整体缩放</span>
  magnifier<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setMouseButton</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>LeftButton<span class="token punctuation">)</span><span class="token punctuation">;</span>                                    <span class="token comment">//设置为左键缩放</span>
  magnifier<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setWheelFactor</span><span class="token punctuation">(</span><span class="token number">1.5</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                               <span class="token comment">//设置鼠标滚轮缩放系数</span>
  
  QwtPlotPanner <span class="token operator">*</span>panner <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token function">QwtPlotPanner</span><span class="token punctuation">(</span>ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">canvas</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>              <span class="token comment">//默认的左键移动功能</span>
  panner<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setMouseButton</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>RightButton<span class="token punctuation">)</span><span class="token punctuation">;</span>                                      <span class="token comment">//设置为右键移动</span>
  
  <span class="token comment">//鼠标监听</span>
  <span class="token function">setMouseTracking</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  ui<span class="token operator">-</span><span class="token operator">&gt;</span>centralwidget<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setMouseTracking</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setMouseTracking</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">canvas</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setMouseTracking</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  
  
  m_timer <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token function">QTimer</span><span class="token punctuation">(</span><span class="token keyword">this</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                               <span class="token comment">//初始化定时器</span>
  <span class="token function">connect</span><span class="token punctuation">(</span>m_timer<span class="token punctuation">,</span> <span class="token operator">&amp;</span>QTimer<span class="token operator">::</span>timeout<span class="token punctuation">,</span>
          <span class="token punctuation">[</span><span class="token operator">=</span><span class="token punctuation">]</span><span class="token punctuation">(</span><span class="token punctuation">)</span>
          <span class="token punctuation">{<!-- --></span>
              <span class="token keyword">double</span> x<span class="token punctuation">[</span><span class="token number">50</span><span class="token punctuation">]</span><span class="token punctuation">,</span> y1<span class="token punctuation">[</span><span class="token number">50</span><span class="token punctuation">]</span><span class="token punctuation">;</span>                                         <span class="token comment">//创建绘图所用数组,需要快速读写情况下建议使用数组，不使用QVector&lt;double&gt;</span>
              <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">int</span> i<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">;</span> i<span class="token operator">&lt;</span><span class="token number">50</span><span class="token punctuation">;</span> <span class="token operator">++</span>i<span class="token punctuation">)</span>
              <span class="token punctuation">{<!-- --></span>
                x<span class="token punctuation">[</span>i<span class="token punctuation">]</span> <span class="token operator">=</span> i<span class="token punctuation">;</span>
                y1<span class="token punctuation">[</span>i<span class="token punctuation">]</span> <span class="token operator">=</span> QRandomGenerator<span class="token operator">::</span><span class="token function">global</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">bounded</span><span class="token punctuation">(</span><span class="token number">100</span><span class="token punctuation">,</span><span class="token number">1000</span><span class="token punctuation">)</span><span class="token punctuation">;</span>      <span class="token comment">//生成随机数</span>
              <span class="token punctuation">}</span>
              m_curvep<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setSamples</span><span class="token punctuation">(</span>x<span class="token punctuation">,</span> y1<span class="token punctuation">,</span> <span class="token number">50</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">//Info4</span>
              ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">replot</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
          <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
      m_timer<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">start</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                    <span class="token comment">//开启定时器，每1毫秒显示一帧图像</span>
  
  }
  MainWindow::~MainWindow()
  
  {
  
  delete ui;
  
  }
  //鼠标释放事件，显示最近数据点的坐标
  
  void MainWindow::mouseReleaseEvent(QMouseEvent *p_eventP)
  
  {
  
  QPoint l_pointMouse = ui->m_plot->canvas()->mapFromGlobal(QCursor::pos());             //将全局屏幕坐标位置转换为控件坐标。
  <span class="token keyword">if</span><span class="token punctuation">(</span>l_pointMouse<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">&gt;=</span> <span class="token number">0</span> <span class="token operator">&amp;&amp;</span> l_pointMouse<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">&lt;</span> ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">canvas</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">width</span><span class="token punctuation">(</span><span class="token punctuation">)</span>           <span class="token comment">//如果鼠标在控件内就显示</span>
          <span class="token operator">&amp;&amp;</span> l_pointMouse<span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">&gt;=</span> <span class="token number">0</span> <span class="token operator">&amp;&amp;</span> l_pointMouse<span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">&lt;</span> ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">canvas</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">height</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span>
  <span class="token punctuation">{<!-- --></span>
      <span class="token keyword">int</span> l_nX <span class="token operator">=</span> m_curvep<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">closestPoint</span><span class="token punctuation">(</span>l_pointMouse<span class="token punctuation">)</span><span class="token punctuation">;</span>                                    <span class="token comment">//获取离鼠标最近点横坐标</span>
      <span class="token keyword">int</span> l_nY <span class="token operator">=</span> m_curvep<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">sample</span><span class="token punctuation">(</span>l_nX<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                              <span class="token comment">//获取离鼠标最近点纵坐标</span>
      QString l_strPos <span class="token operator">=</span> <span class="token function">QString</span><span class="token punctuation">(</span><span class="token string">"x：%0 y：%1"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">arg</span><span class="token punctuation">(</span>l_nX<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">arg</span><span class="token punctuation">(</span>l_nY<span class="token punctuation">)</span><span class="token punctuation">;</span>
      QString l_stStyle <span class="token operator">=</span> <span class="token string">"&lt;p style=\"background:#00FFFF; border-radius: 1px 5px;font:12pt '宋体'\"&gt;%1&lt;/p&gt;"</span><span class="token punctuation">;</span>
      QToolTip<span class="token operator">::</span><span class="token function">showText</span><span class="token punctuation">(</span><span class="token function">cursor</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">pos</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> l_stStyle<span class="token punctuation">.</span><span class="token function">arg</span><span class="token punctuation">(</span>l_strPos<span class="token punctuation">)</span><span class="token punctuation">,</span> ui<span class="token operator">-</span><span class="token operator">&gt;</span>m_plot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">canvas</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token function">QRect</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">,</span><span class="token number">0</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token number">10000</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">//在点击位置显示提示信息</span>
  <span class="token punctuation">}</span>
  
  }
  //停止定时器
  
  void MainWindow::on_pushButton_clicked()
  
  {
  
  m_timer->stop();
  
  }
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QCustomPlot

1、下载源码

• 下载地址

• 下载QCustomPlot.tar.gz、QCustomPlot-sharedlib.tar.gz两个文件并解压。

  

2、使用源码

• Qt新建一个工程文件，解压QCustomPlot.tar.gz后将qcustomplot.h与qcustomplot.cpp拷贝到工程目录下，右键 -> 添加现有文件…，将这两个文件添加至工程。

  

• 在pro中需要添加（由于QCustomPlot中存在导出功能，使用了printsupport模块）：

  QT += printsupport
  1

• 进入.ui文件，选择widget控件，右键提升为QCustomPlot。

  

  

• 运行程序就可以看见控件效果了，由于直接使用QCustomPlot源码，所以编译运行速度会比较慢。

  

3、将QCustomPlot编译成共享库

• 解压QCustomPlot-sharedlib.tar.gz，将QCustomPlot.tar.gz中的qcustomplot.cpp/.h文件复制到和QCustomPlot-sharedlib.tar.gz解压后的文件夹同级目录下。

  

• 进入qcustomplot-sharedlib/sharedlib-compilation –> 使用Qt打开sharedlib-compilation.pro文件。

  

  

• 选择Debug或Release任意模式，然后点击构建。

  

• 进入build-sharedlib-compilation-Desktop_Qt_5_14_2_MinGW_64_bit-Debug目录，将debug和release目录下的libqcustomplotd2.a、qcustomplotd2.dll、libqcustomplot2.a、qcustomplot2.dll四个文件（代d的为debug版本）复制到新建的qcustomplot目录下，再将qcustomplot.h、cpp两个源码文件也复制到qcustomplot目录下。

  

  <img src="Qwt%E3%80%81QChart%E3%80%81QCustomPlot%E4%BD%BF%E7%94%A8%E6%96%87%E6%A1%A3.assets/

• 新建一个Qt工程，在.pro文件添加。

  QT += printsupport
  1

• 选中工程名，右键 –> 添加库 –> 静态库 –> 浏览 –> 选择之前编译好的libqcustomplot2.a文件，点击确定，会在.pro文件中生成下列几行代码。

  

• 将圈中位置由-lqcustomplot2d改为lqcustomplotd2。

  

• 选择widget控件，右键提升为QCustomPlot，编译运行就可以使用QCustomPlot了。

4、示例

• 进入.ui文件，选择widget控件，命名为customPlot，右键提升为QCustomPlot，添加PushButton，命名为pushButton_Stop。

  

• widget.h文件源码

#ifndef WIDGET_H
#define WIDGET_H
#include <QWidget>

#include <qtimer.h>
QT_BEGIN_NAMESPACE

namespace Ui { class Widget; }

QT_END_NAMESPACE
class Widget : public QWidget

{

Q_OBJECT
public:

Widget(QWidget *parent = nullptr);

~Widget();
protected:

void Init();                                  //初始化绘图

void connectSlot();                           // 绑定信号槽
private:
<span class="token keyword">void</span> <span class="token function">on_mouseRelease</span><span class="token punctuation">(</span>QMouseEvent <span class="token operator">*</span>event<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">void</span> <span class="token function">on_mouseDoubleClick</span><span class="token punctuation">(</span>QMouseEvent <span class="token operator">*</span>event<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">void</span> <span class="token function">updateData</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

private:

Ui::Widget *ui;

QTimer m_timer;                               //声明定时器
QVector<span class="token operator">&lt;</span><span class="token keyword">double</span><span class="token operator">&gt;</span> arrX<span class="token punctuation">,</span> arrY1<span class="token punctuation">,</span> arrY2<span class="token punctuation">;</span>           <span class="token comment">//创建绘图所用数组</span>

};

#endif // WIDGET_H
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• widget.cpp文件源码

#include "widget.h"
#include "ui_widget.h"
#include <QCursor>
#define DATA_LEN 1000           // 绘制的数据量

#define X_AXIS_MIN  0           // X轴最小值

#define X_AXIS_MAX  1000        // X轴最大值

#define Y_AXIS_MIN  0

#define Y_AXIS_MAX  1100
Widget::Widget(QWidget *parent)

: QWidget(parent)

, ui(new Ui::Widget)

{

ui->setupUi(this);
<span class="token function">Init</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">connectSlot</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

}
Widget::~Widget()

{

delete ui;

}
void Widget::Init()

{
<span class="token comment">//设置标题</span>
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">plotLayout</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">insertRow</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">plotLayout</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">addElement</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">,</span> <span class="token keyword">new</span> <span class="token function">QCPTextElement</span><span class="token punctuation">(</span>ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token punctuation">,</span> <span class="token string">"标题"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

//    ui->customPlot->setBackground(QColor(0,0,0,255));                        //设置背景色

ui->customPlot->xAxis->setRange(X_AXIS_MIN, X_AXIS_MAX);                   //设置横坐标轴范围

ui->customPlot->yAxis->setRange(Y_AXIS_MIN, Y_AXIS_MAX);                   //设置纵坐标轴范围
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setInteractions</span><span class="token punctuation">(</span>QCP<span class="token operator">::</span>iRangeDrag <span class="token operator">|</span>QCP<span class="token operator">::</span>iRangeZoom<span class="token punctuation">)</span><span class="token punctuation">;</span>         <span class="token comment">//设置鼠标拖动,设置鼠标滚轮缩放</span>
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setInteraction</span><span class="token punctuation">(</span>QCP<span class="token operator">::</span>iSelectPlottables<span class="token punctuation">,</span> <span class="token boolean">false</span><span class="token punctuation">)</span><span class="token punctuation">;</span>             <span class="token comment">//设置是否可选择图表</span>
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span>legend<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setVisible</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                  <span class="token comment">//设定右上角图形标注可见</span>

ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setSelectionRectMode</span><span class="token punctuation">(</span>QCP<span class="token operator">::</span>SelectionRectMode<span class="token operator">::</span>srmZoom<span class="token punctuation">)</span><span class="token punctuation">;</span>     <span class="token comment">//模式：框选放大</span>

<span class="token comment">//设置添加的图表</span>
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">addGraph</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                 <span class="token comment">//添加图表1</span>
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">addGraph</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                 <span class="token comment">//添加图表2</span>
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">graph</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"数据1"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                  <span class="token comment">//设置图表1名称</span>
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">graph</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"数据2"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                  <span class="token comment">//设置图表2名称</span>
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">graph</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setPen</span><span class="token punctuation">(</span><span class="token function">QPen</span><span class="token punctuation">(</span><span class="token function">QColor</span><span class="token punctuation">(</span><span class="token number">255</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">255</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>             <span class="token comment">//设置图表1颜色</span>
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">graph</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setPen</span><span class="token punctuation">(</span><span class="token function">QPen</span><span class="token punctuation">(</span><span class="token function">QColor</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">255</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">255</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>             <span class="token comment">//设置图表2颜色</span>

ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span>xAxis<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setLabel</span><span class="token punctuation">(</span><span class="token string">"x"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                       <span class="token comment">//设置横坐标轴标题</span>
ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span>yAxis<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setLabel</span><span class="token punctuation">(</span><span class="token string">"y"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                       <span class="token comment">//设置纵坐标轴标题</span>

arrX<span class="token punctuation">.</span><span class="token function">resize</span><span class="token punctuation">(</span>DATA_LEN<span class="token punctuation">)</span><span class="token punctuation">;</span>
arrY1<span class="token punctuation">.</span><span class="token function">resize</span><span class="token punctuation">(</span>DATA_LEN<span class="token punctuation">)</span><span class="token punctuation">;</span>
arrY2<span class="token punctuation">.</span><span class="token function">resize</span><span class="token punctuation">(</span>DATA_LEN<span class="token punctuation">)</span><span class="token punctuation">;</span>
m_timer<span class="token punctuation">.</span><span class="token function">start</span><span class="token punctuation">(</span><span class="token number">50</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                          <span class="token comment">//开启定时器，每10毫秒显示一帧图像</span>

}
void Widget::connectSlot()

{

//显示鼠标点击位置的坐标信息，只能用SIGNAL格式

connect(ui->customPlot, &QCustomPlot::mouseRelease, this, &Widget::on_mouseRelease);

connect(ui->customPlot, &QCustomPlot::mouseDoubleClick, this, &Widget::on_mouseDoubleClick);

connect(&m_timer, &QTimer::timeout, this, &Widget::updateData);     // 定时器绘制图表

}
/**


@brief        鼠标中键点击显示点的信息


@param event

/

void Widget::on_mouseRelease(QMouseEvent event)

{

if(event->button() == Qt::MiddleButton)

{

//获取点击的下标

int l_nX = qRound(ui->customPlot->xAxis->pixelToCoord(event->x()));              //将鼠标点击处QCustomPlot小部件的像素坐标中的值转换为轴坐标，取四舍五入值
 QString l_strToolTip <span class="token operator">=</span> <span class="token function">QString</span><span class="token punctuation">(</span><span class="token string">"x：%0"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">arg</span><span class="token punctuation">(</span>l_nX<span class="token punctuation">)</span><span class="token punctuation">;</span>                                <span class="token comment">//添加提示信息</span>
 <span class="token keyword">if</span><span class="token punctuation">(</span>l_nX <span class="token operator">&gt;=</span> <span class="token number">0</span><span class="token punctuation">)</span>                                                                    <span class="token comment">//如果鼠标点击位置为负则不显示</span>
 <span class="token punctuation">{<!-- --></span>
     <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span>i <span class="token operator">&lt;</span> ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span>xAxis<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">graphs</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">count</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>i<span class="token operator">++</span><span class="token punctuation">)</span>              <span class="token comment">//判断共有多少路数据</span>
     <span class="token punctuation">{<!-- --></span>
         <span class="token keyword">int</span> l_nY <span class="token operator">=</span> ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">graph</span><span class="token punctuation">(</span>i<span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">data</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">at</span><span class="token punctuation">(</span>l_nX<span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span>value<span class="token punctuation">;</span>            <span class="token comment">//获得x轴坐标位置对应的曲线上y的值</span>
         l_strToolTip <span class="token operator">+</span><span class="token operator">=</span> <span class="token function">QString</span><span class="token punctuation">(</span><span class="token string">"\ny%0：%1"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">arg</span><span class="token punctuation">(</span>i<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">arg</span><span class="token punctuation">(</span>l_nY<span class="token punctuation">)</span><span class="token punctuation">;</span>
     <span class="token punctuation">}</span>
     QToolTip<span class="token operator">::</span><span class="token function">showText</span><span class="token punctuation">(</span><span class="token function">cursor</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">pos</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> l_strToolTip<span class="token punctuation">,</span> ui<span class="token operator">-</span><span class="token operator">&gt;</span>customPlot<span class="token punctuation">,</span> <span class="token function">QRect</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">,</span><span class="token number">0</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token number">10000</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">//在点击位置显示提示信息</span>
 <span class="token punctuation">}</span>

}

}


/**

@brief         鼠标右键双击还原图表大小(坐标轴刻度)
@param event

/

void Widget::on_mouseDoubleClick(QMouseEvent event)

{

if(event->button() == Qt::RightButton)

{

ui->customPlot->xAxis->setRange(X_AXIS_MIN, X_AXIS_MAX);                    //设置横坐标轴范围

ui->customPlot->yAxis->setRange(Y_AXIS_MIN, Y_AXIS_MAX);                    //设置纵坐标轴范围

ui->customPlot->replot();                                                   //更新图表

}

}

/**

@brief 生成随机数并绘制图表

*/

void Widget::updateData()

{

for (int i=0; i< DATA_LEN; ++i)

{

arrX[i] = i;

arrY1[i] = QRandomGenerator::global()->bounded(500, 1000);          //生成随机数

arrY2[i] = QRandomGenerator::global()->bounded(10, 500);

}

ui->customPlot->graph(0)->setData(arrX, arrY1);                       //添加数据

ui->customPlot->graph(1)->setData(arrX, arrY2);                       //添加数据

ui->customPlot->replot();                                             //更新图表

}

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• QCPGraph::setData第三参数对性能的引响：

  • 1000数据：alreadySorted设为true时需要16.8毫秒，设为false时需要13.6毫秒；
  • 10000数据：alreadySorted设为true时需要21.6毫秒，设为false时需要22.6毫秒；
  • 100000数据：alreadySorted设为true时需要22.5毫秒，设为false时需要43.7毫秒；
  • 500000数据：alreadySorted设为true时需要43.3毫秒，设为false时需要197.2毫秒；
  • 在数据量小于10000时alreadySorted为false和true性能相差不大，数据量为100000时alreadySorted为true性能为false的2倍左右，数据量为500000时alreadySorted为true的性能是false的4.5倍左右，所以如果可以保证通过键对传递的数据点进行升序排序，则可以将alreadySorted设置为true，以通过保存排序运行来提高性能。

  void QCPGraph::setData (const QVector< double > & keys, 
                          const QVector< double > & values, 
                          bool alreadySorted = false )
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QChart

1、安装

• 如果需要在QT中使用QChart类，需要在安装Qt的时候勾选QChart选项，在工程的 .pro 文件里面添加 QT += charts 语句，包含 QChart 头文件就行了。

2、示例

• 在程序中创建ChartView类，继承与QChartView，实现绘制图表的缩放、还原、移动和鼠标点击显示最近点信息功能；

• MainWidget.h文件源码。

  #ifndef MAINWINDOW_H
  #define MAINWINDOW_H
  #include <QMainWindow>
  
  #include <QtCharts/QLineSeries>
  
  #include <QtCharts/QChart>
  
  #include <QtCharts/QValueAxis>
  
  #include <QtCharts/QChartView>
  
  #include "chartview.h"
  QT_CHARTS_USE_NAMESPACE
  
  QT_BEGIN_NAMESPACE
  
  namespace Ui { class MainWindow; }
  
  QT_END_NAMESPACE
  class MainWindow : public QMainWindow
  
  {
  
  Q_OBJECT
  public:
  
  MainWindow(QWidget *parent = nullptr);
  
  ~MainWindow();
  QTimer <span class="token operator">*</span>m_timer<span class="token punctuation">;</span>                              <span class="token comment">//定时器</span>
  QLineSeries <span class="token operator">*</span>series<span class="token punctuation">;</span>                          <span class="token comment">//折线数据序列</span>
  QChart <span class="token operator">*</span>chart<span class="token punctuation">;</span>                                <span class="token comment">//图表</span>
  
  private slots:
  
  void on_pushButton_clicked();
  private:
  
  Ui::MainWindow *ui;
  
  };
  
  #endif // MAINWINDOW_H
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• MainWidget.cpp文件源码

  #include "mainwindow.h"
  #include "ui_mainwindow.h"
  #include <QDebug>
  #include <QRandomGenerator>
  #include <QTimer>
  #define DATA_SIZE 10         //绘制数据点数
  MainWindow::MainWindow(QWidget *parent)
  
  : QMainWindow(parent)
  
  , ui(new Ui::MainWindow)
  
  {
  
  ui->setupUi(this);
  series <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token function">QLineSeries</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                  <span class="token comment">//创建折线图数据序列</span>
  series<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setUseOpenGL</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                  <span class="token comment">//openGl 加速</span>
  
  chart <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token function">QChart</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                        <span class="token comment">//创建图表</span>
  chart<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">legend</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">hide</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                     <span class="token comment">//隐藏图例</span>
  chart<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">addSeries</span><span class="token punctuation">(</span>series<span class="token punctuation">)</span><span class="token punctuation">;</span>                                                    <span class="token comment">//添加数据序列</span>
  chart<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">createDefaultAxes</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                  <span class="token comment">//基于已添加到图表中的系列为图表创建轴，必须在将所有系列添加到图表后调用此函数</span>
  chart<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setTitle</span><span class="token punctuation">(</span><span class="token string">"标题"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                      <span class="token comment">//设置图表标题</span>
  
  QValueAxis<span class="token operator">*</span> m_axisX <span class="token operator">=</span> <span class="token punctuation">(</span>QValueAxis<span class="token operator">*</span><span class="token punctuation">)</span>chart<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">axes</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>Horizontal<span class="token punctuation">,</span> series<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">at</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token comment">//获取图表中的横坐标轴</span>
  QValueAxis<span class="token operator">*</span> m_axisY <span class="token operator">=</span> <span class="token punctuation">(</span>QValueAxis<span class="token operator">*</span><span class="token punctuation">)</span>chart<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">axes</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>Vertical<span class="token punctuation">,</span> series<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">at</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>  <span class="token comment">//获取图表中的纵坐标轴</span>
  m_axisX<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setRange</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">,</span>DATA_SIZE<span class="token punctuation">)</span><span class="token punctuation">;</span>                                              <span class="token comment">//设置坐标轴范围</span>
  m_axisX<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setGridLineVisible</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                           <span class="token comment">//设置网格线可见</span>
  m_axisX<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setTickCount</span><span class="token punctuation">(</span><span class="token number">11</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                   <span class="token comment">//设置一级刻度分为几个</span>
  m_axisX<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setMinorTickCount</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                               <span class="token comment">//设置二级刻度分为几个</span>
  m_axisX<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setTitleText</span><span class="token punctuation">(</span><span class="token string">"X轴"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                <span class="token comment">//设置横轴标题</span>
  m_axisY<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setRange</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">,</span><span class="token number">1000</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  m_axisY<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setGridLineVisible</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  m_axisY<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setTickCount</span><span class="token punctuation">(</span><span class="token number">6</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  m_axisY<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setMinorTickCount</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  m_axisY<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setTitleText</span><span class="token punctuation">(</span><span class="token string">"Y轴"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  
  
  ChartView <span class="token operator">*</span>l_view <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token function">ChartView</span><span class="token punctuation">(</span>chart<span class="token punctuation">)</span><span class="token punctuation">;</span>                             <span class="token comment">//使用自定义类</span>
  l_view<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setChart</span><span class="token punctuation">(</span>chart<span class="token punctuation">)</span><span class="token punctuation">;</span>                                                       <span class="token comment">//添加图表</span>
  l_view<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setRenderHint</span><span class="token punctuation">(</span>QPainter<span class="token operator">::</span>Antialiasing<span class="token punctuation">)</span><span class="token punctuation">;</span>                                <span class="token comment">//设置渲染器，优化图像质量</span>
  <span class="token comment">//ui-&gt;chartView-&gt;setRubberBand(QChartView::RectangleRubberBand);              //鼠标左键选框放大，右键点击缩小，但左键如果点在绘制的线上时无法拉取选框</span>
  
  ui<span class="token operator">-</span><span class="token operator">&gt;</span>gridLayout_2<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">addWidget</span><span class="token punctuation">(</span>l_view<span class="token punctuation">)</span><span class="token punctuation">;</span>
  
  <span class="token comment">//使用定时器更新数据</span>
  m_timer <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token function">QTimer</span><span class="token punctuation">(</span><span class="token keyword">this</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                  <span class="token comment">//初始化定时器</span>
  <span class="token function">connect</span><span class="token punctuation">(</span>m_timer<span class="token punctuation">,</span> <span class="token operator">&amp;</span>QTimer<span class="token operator">::</span>timeout<span class="token punctuation">,</span>
  <span class="token punctuation">[</span><span class="token operator">&amp;</span><span class="token punctuation">]</span><span class="token punctuation">(</span><span class="token punctuation">)</span>
  <span class="token punctuation">{<!-- --></span>
      QVector<span class="token operator">&lt;</span>QPointF<span class="token operator">&gt;</span> <span class="token function">point</span><span class="token punctuation">(</span>DATA_SIZE <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
      <span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator">&lt;</span> DATA_SIZE <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">;</span> i<span class="token operator">++</span><span class="token punctuation">)</span>
      <span class="token punctuation">{<!-- --></span>
          point<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">.</span><span class="token function">setX</span><span class="token punctuation">(</span>i<span class="token punctuation">)</span><span class="token punctuation">;</span>
          point<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">.</span><span class="token function">setY</span><span class="token punctuation">(</span><span class="token punctuation">(</span><span class="token keyword">int</span><span class="token punctuation">)</span>QRandomGenerator<span class="token operator">::</span><span class="token function">global</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">bounded</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">1000</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
      <span class="token punctuation">}</span>
      series<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">replace</span><span class="token punctuation">(</span>point<span class="token punctuation">)</span><span class="token punctuation">;</span>                                                 <span class="token comment">//更新数据</span>
  <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  m_timer<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">start</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                                                          <span class="token comment">//开启定时器，每1毫秒显示一帧图像</span>
  
  }
  MainWindow::~MainWindow()
  
  {
  
  delete ui;
  
  }
  //暂停定时器
  
  void MainWindow::on_pushButton_clicked()
  
  {
  
  m_timer->stop();
  
  }
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• ChartView.h文件源码。

  #ifndef CHARTVIEW_H
  #define CHARTVIEW_H
  #include <QChartView>
  
  #include <QMouseEvent>
  
  #include <QGraphicsSimpleTextItem>
  QT_CHARTS_USE_NAMESPACE
  class ChartView : public QChartView
  
  {
  
  Q_OBJECT
  public:
  
  ChartView(QChart chart, QWidget parent = nullptr);
  
  ~ChartView();
  protected:
  
  void mouseDoubleClickEvent(QMouseEvent event);
  
  void mousePressEvent(QMouseEvent event);
  
  void mouseMoveEvent(QMouseEvent event);
  
  void mouseReleaseEvent(QMouseEvent event);
  
  void wheelEvent(QWheelEvent *event);
  private:
  QPoint m_pointUsed<span class="token punctuation">;</span>                             <span class="token comment">//保存旧坐标</span>
  <span class="token keyword">bool</span> m_isPress<span class="token punctuation">;</span>                                 <span class="token comment">//是否按下鼠标</span>
  <span class="token keyword">double</span> m_dMinX<span class="token punctuation">,</span> m_dMaxX<span class="token punctuation">,</span> m_dMinY<span class="token punctuation">,</span> m_dMaxY<span class="token punctuation">;</span>      <span class="token comment">//保存图表轴初始大小</span>
  
  };
  #endif // CHARTVIEW_H
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• ChartView.cpp文件源码。

  #include "chartview.h"
  #include <QValueAxis>
  #include <QWidget>
  #include <QDebug>
  #include <QLineSeries>
  #include <math.h>
  #include <QToolTip>
  ChartView::ChartView(QChart chart, QWidget parent):QChartView(chart)
  
  {
  
  //保存图表初始大小
  
  QValueAxis l_axisX = (QValueAxis)this->chart()->axes(Qt::Horizontal).at(0);
  
  m_dMinX = l_axisX->min();
  
  m_dMaxX = l_axisX->max();
  
  QValueAxis l_axisY = (QValueAxis)this->chart()->axes(Qt::Vertical).at(0);
  
  m_dMinY = l_axisY->min();
  
  m_dMaxY = l_axisY->max();
  
  }
  ChartView::~ChartView()
  
  {
  }
  //鼠标按下
  
  void ChartView::mousePressEvent(QMouseEvent *event)
  
  {
  <span class="token keyword">if</span> <span class="token punctuation">(</span>event<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">button</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">==</span> Qt<span class="token operator">::</span>LeftButton<span class="token punctuation">)</span>                       <span class="token comment">//鼠标左键按下</span>
  <span class="token punctuation">{<!-- --></span>
      m_pointUsed <span class="token operator">=</span> event<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">pos</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                              <span class="token comment">//保存当前坐标</span>
      m_isPress <span class="token operator">=</span> <span class="token boolean">true</span><span class="token punctuation">;</span>
  <span class="token punctuation">}</span>
  <span class="token keyword">else</span> <span class="token keyword">if</span><span class="token punctuation">(</span>event<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">button</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">==</span> Qt<span class="token operator">::</span>MidButton<span class="token punctuation">)</span>                    <span class="token comment">//鼠标中键按下</span>
  <span class="token punctuation">{<!-- --></span>
      QLineSeries<span class="token operator">*</span> l_series <span class="token operator">=</span> <span class="token punctuation">(</span>QLineSeries<span class="token operator">*</span><span class="token punctuation">)</span><span class="token keyword">this</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">chart</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">series</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">at</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>      <span class="token comment">//获取序列中的值</span>
      QVector<span class="token operator">&lt;</span>QPointF<span class="token operator">&gt;</span> l_vpointF <span class="token operator">=</span> l_series<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">pointsVector</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
      QPointF l_curVal <span class="token operator">=</span> <span class="token keyword">this</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">chart</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">mapToValue</span><span class="token punctuation">(</span>event<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">pos</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>               <span class="token comment">//返回鼠标处的值</span>
      QPointF l_pointF <span class="token operator">=</span> l_vpointF<span class="token punctuation">.</span><span class="token function">at</span><span class="token punctuation">(</span><span class="token function">qRound</span><span class="token punctuation">(</span>l_curVal<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>                    <span class="token comment">//获取离鼠标的横坐标最近的点</span>
  
      QString l_strPos <span class="token operator">=</span> <span class="token function">QString</span><span class="token punctuation">(</span><span class="token string">"x：%0 y：%1"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">arg</span><span class="token punctuation">(</span>l_pointF<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">arg</span><span class="token punctuation">(</span>l_pointF<span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
      QString l_stStyle <span class="token operator">=</span> <span class="token string">"&lt;p style=\"background:#00FFFF; border-radius: 1px 5px;font:12pt '宋体'\"&gt;%1&lt;/p&gt;"</span><span class="token punctuation">;</span>
      QToolTip<span class="token operator">::</span><span class="token function">showText</span><span class="token punctuation">(</span><span class="token function">cursor</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">pos</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> l_stStyle<span class="token punctuation">.</span><span class="token function">arg</span><span class="token punctuation">(</span>l_strPos<span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token keyword">this</span><span class="token punctuation">,</span> <span class="token function">QRect</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">,</span><span class="token number">0</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token number">10000</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">//在点击位置显示提示信息</span>
  <span class="token punctuation">}</span>
  
  }
  //鼠标双击
  
  void ChartView::mouseDoubleClickEvent(QMouseEvent *event)
  
  {
  
  if (event->button() == Qt::RightButton)                        //鼠标右键双击恢复最初大小
  
  {
  
  this->chart()->axes(Qt::Horizontal).at(0)->setRange(m_dMinX, m_dMaxX);
  
  this->chart()->axes(Qt::Vertical).at(0)->setRange(m_dMinY, m_dMaxY);
  
  }
  
  }
  //鼠标移动
  
  void ChartView::mouseMoveEvent(QMouseEvent *event)
  
  {
  
  if(m_isPress)
  
  {
  
  QPoint l_pointDiff = event->pos() - m_pointUsed;              //当前坐标与按下鼠标处的坐标差
  
  this->chart()->scroll(-l_pointDiff.x(), l_pointDiff.y());     //移动图表
  
  }
  
  m_pointUsed = event->pos();                                       //保存当前坐标
  
  }
  //鼠标释放
  
  void ChartView::mouseReleaseEvent(QMouseEvent *event)
  
  {
  
  m_isPress = false;
  
  }
  //鼠标滚轮缩放
  
  void ChartView::wheelEvent(QWheelEvent *event)
  
  {
  
  QPointF l_curVal = this->chart()->mapToValue(event->pos());               //返回鼠标处的值
  QValueAxis <span class="token operator">*</span>l_axisX <span class="token operator">=</span> <span class="token punctuation">(</span>QValueAxis<span class="token operator">*</span><span class="token punctuation">)</span><span class="token keyword">this</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">chart</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">axes</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>Horizontal<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">at</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  <span class="token keyword">double</span> l_fMinX <span class="token operator">=</span> l_axisX<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">min</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  <span class="token keyword">double</span> l_fMaxX <span class="token operator">=</span> l_axisX<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">max</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  QValueAxis <span class="token operator">*</span>l_axisY <span class="token operator">=</span> <span class="token punctuation">(</span>QValueAxis<span class="token operator">*</span><span class="token punctuation">)</span><span class="token keyword">this</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">chart</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">axes</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>Vertical<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">at</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  <span class="token keyword">double</span> l_fMinY <span class="token operator">=</span> l_axisY<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">min</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  <span class="token keyword">double</span> l_fMaxY <span class="token operator">=</span> l_axisY<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">max</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  
  <span class="token keyword">double</span> l_fZoomMinX<span class="token punctuation">,</span>l_fZoomMaxX<span class="token punctuation">,</span>l_fZoomMinY<span class="token punctuation">,</span>l_fZoomMaxY<span class="token punctuation">;</span>
  <span class="token keyword">if</span><span class="token punctuation">(</span>event<span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">delta</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">&gt;</span> <span class="token number">0</span><span class="token punctuation">)</span>                                                   <span class="token comment">//获取放大值</span>
  <span class="token punctuation">{<!-- --></span>
      l_fZoomMinX <span class="token operator">=</span> l_curVal<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">-</span> <span class="token punctuation">(</span>l_curVal<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">-</span> l_fMinX<span class="token punctuation">)</span> <span class="token operator">/</span> <span class="token number">1.5</span><span class="token punctuation">;</span>
      l_fZoomMaxX <span class="token operator">=</span> l_curVal<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">+</span> <span class="token punctuation">(</span>l_fMaxX <span class="token operator">-</span> l_curVal<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token operator">/</span> <span class="token number">1.5</span><span class="token punctuation">;</span>
      l_fZoomMinY <span class="token operator">=</span> l_curVal<span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">-</span> <span class="token punctuation">(</span>l_curVal<span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">-</span> l_fMinY<span class="token punctuation">)</span> <span class="token operator">/</span> <span class="token number">1.5</span><span class="token punctuation">;</span>
      l_fZoomMaxY <span class="token operator">=</span> l_curVal<span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">+</span> <span class="token punctuation">(</span>l_fMaxY <span class="token operator">-</span> l_curVal<span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token operator">/</span> <span class="token number">1.5</span><span class="token punctuation">;</span>
  <span class="token punctuation">}</span>
  <span class="token keyword">else</span>                                                                     <span class="token comment">//获取缩小值</span>
  <span class="token punctuation">{<!-- --></span>
      l_fZoomMinX <span class="token operator">=</span> l_curVal<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">-</span> <span class="token punctuation">(</span>l_curVal<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">-</span> l_fMinX<span class="token punctuation">)</span> <span class="token operator">*</span> <span class="token number">1.5</span><span class="token punctuation">;</span>
      l_fZoomMaxX <span class="token operator">=</span> l_curVal<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">+</span> <span class="token punctuation">(</span>l_fMaxX <span class="token operator">-</span> l_curVal<span class="token punctuation">.</span><span class="token function">x</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token operator">*</span> <span class="token number">1.5</span><span class="token punctuation">;</span>
      l_fZoomMinY <span class="token operator">=</span> l_curVal<span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">-</span> <span class="token punctuation">(</span>l_curVal<span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">-</span> l_fMinY<span class="token punctuation">)</span> <span class="token operator">*</span> <span class="token number">1.5</span><span class="token punctuation">;</span>
      l_fZoomMaxY <span class="token operator">=</span> l_curVal<span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">+</span> <span class="token punctuation">(</span>l_fMaxY <span class="token operator">-</span> l_curVal<span class="token punctuation">.</span><span class="token function">y</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token operator">*</span> <span class="token number">1.5</span><span class="token punctuation">;</span>
  <span class="token punctuation">}</span>
  <span class="token keyword">this</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">chart</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">axes</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>Vertical<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">at</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setRange</span><span class="token punctuation">(</span>l_fZoomMinY<span class="token punctuation">,</span> l_fZoomMaxY<span class="token punctuation">)</span><span class="token punctuation">;</span>   <span class="token comment">//设置轴范围</span>
  <span class="token keyword">this</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">chart</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">axes</span><span class="token punctuation">(</span>Qt<span class="token operator">::</span>Horizontal<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">at</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token operator">-</span><span class="token operator">&gt;</span><span class="token function">setRange</span><span class="token punctuation">(</span>l_fZoomMinX<span class="token punctuation">,</span> l_fZoomMaxX<span class="token punctuation">)</span><span class="token punctuation">;</span>
  
  }
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• setUseOpenGL对性能的引响：

  • 1000数据：setUseOpenGL设为true时需要12.5毫秒，设为false时需要14毫秒；
  • 10000数据：setUseOpenGL设为true时需要13.5毫秒，设为false时需要56.8毫秒；
  • 100000数据：setUseOpenGL设为true时需要20.7毫秒，设为false时需要507.4毫秒；
  • 500000数据：setUseOpenGL设为true时需要194.25毫秒，设为false时需要507.4毫秒；

</article>