qt 使用笔记

• [33ddd](### 窗口分割器使用)

窗口分割器使用

        // 测试窗口分割 splitter
        QDialog* pDlg = new QDialog();
        QSplitter* splitterMain = new QSplitter(Qt::Horizontal,pDlg);      
        //splitterMain->setFixedSize(100,200);
        splitterMain->setStretchFactor(1, 1);
        QTextEdit* textLeft = new QTextEdit(tr("左侧窗口"), splitterMain); 
        QTextEdit* textRight = new QTextEdit(tr("右侧窗口"), splitterMain);
        if (pDlg->exec())
        {
        }

        delete textLeft;
        delete textRight;
        delete splitterMain;
        delete pDlg;

鼠标测量两点间角度

void QAPView::mousePressEvent(QMouseEvent* event)
{
        QPointF point = mapToScene(event->pos());
        CPose pos = MapSenceCoord2Pose(point);
        emit GrpahicsViewMouseMove(point, pos);
        QPointF ptScene = point;

        if (rightKeyPressed)
        {
                m_angleToolEndPoint = ptScene ;
                if (m_pAngleLine == nullptr)
                {
                        m_pAngleLine = new QGraphicsLineItem();
                }
                if (m_pArrow1 == nullptr)
                        m_pArrow1 = new QGraphicsLineItem();
                if (m_pArrow2 == nullptr)
                        m_pArrow2 = new QGraphicsLineItem();
                if (m_pAngleText == nullptr)
                        m_pAngleText = new QGraphicsTextItem();
                QLineF lineAngle = QLineF(m_angleToolStartPoint, m_angleToolEndPoint);
                // 直线太短不显示
                if (qAbs(lineAngle.dy()) < 2 || qAbs(lineAngle.dx()) < 2)
                        return;

                m_pAngleLine->setLine(lineAngle);
                QPen penLine(Qt::red, 3, Qt::SolidLine);
                m_pAngleLine->setPen(penLine);
                m_pScene->addItem(m_pAngleLine);
                // 直线角度
                double angle_line = atan2(lineAngle.dy(), lineAngle.dx());
                qreal arrowSize = 20;
                qreal arrowAng = 15 / 180.0 * PI;
                QPointF arrowP1 = lineAngle.p2() + QPointF(sin(-angle_line + arrowAng - PI / 2) * arrowSize, cos(-angle_line + arrowAng - PI / 2) * arrowSize);  
                QPointF arrowP2 = lineAngle.p2() + QPointF(sin(-angle_line - arrowAng - PI / 2) * arrowSize, cos(-angle_line - arrowAng - PI / 2) * arrowSize);  
                m_pArrow1->setLine(QLineF(lineAngle.p2(), arrowP1));
                m_pArrow2->setLine(QLineF(lineAngle.p2(), arrowP2));
                m_pArrow1->setPen(penLine);
                m_pArrow2->setPen(penLine);
                m_pScene->addItem(m_pArrow1);
                m_pScene->addItem(m_pArrow2);
                m_pArrow1->setVisible(true);
                m_pArrow2->setVisible(true);
                ///  角度值显示
                //m_pAngleText->setPlainText(QString::number(angle_line/PI*180));
                //m_pAngleText->setDefaultTextColor(Qt::red);
                double lineLen = lineAngle.length()*zoomRate* m_szImagePixel.width/1000.; // 像素数x放大倍率x每个像素的size
                QString info = "<h3 style=\"color:#f33b45;\">" + QString("Length:%1 ,Angle:").arg(lineLen) + QString::number(angle_line / PI * 180) + "</h3>";   
                m_pAngleText->setHtml(info);
                m_pAngleText->setPos(ptScene);
                m_pScene->addItem(m_pAngleText);
        }
}

隐藏tabwidget中的某些tab页面

// 方法1：
        // 注意：：：以下两行remove顺序由大到小否则不生效
        //ui->tabWidgetTeachOther->removeTab(2);
        //ui->tabWidgetTeachOther->removeTab(1);

// 方法2：
        ui->tabWidgetTeachOther->setTabEnabled(1, false);
        ui->tabWidgetTeachOther->setTabEnabled(2, false);
        ui->tabWidgetTeachOther->setStyleSheet("QTabBar::tab:disabled {width: 0; color: transparent;}");

记录qt中库使用方法

tabBar竖向时文字横向

#include <QPainter>
#include <QProxyStyle>
#include <QStyleOptionTab>
#include <QRect>
#include <QSize>
class CustomTabStyle : public QProxyStyle
{
public:
        QSize sizeFromContents(ContentsType type, const QStyleOption* option,
                const QSize& size, const QWidget* widget) const
        {
                QSize s = QProxyStyle::sizeFromContents(type, option, size, widget);
                if (type == QStyle::CT_TabBarTab) {
                        s.transpose();
                        s.rwidth() = 100; // 设置每个tabBar中item的大小
                        s.rheight() = 48;
                }
                return s;
        }
        void drawControl(ControlElement element, const QStyleOption* option, QPainter* painter, const QWidget* widget) const
        {
                if (element == CE_TabBarTabLabel) {
                        if (const QStyleOptionTab* tab = qstyleoption_cast<const QStyleOptionTab*>(option)) {
                                QRect allRect = tab->rect;
                                allRect.setWidth(allRect.width() - 5);
                                allRect.setHeight(allRect.height() - 2);
                                //选中状态
                                if (tab->state & QStyle::State_Selected) {
                                        //save用以保护坐标，restore用来退出状态
                                        painter->save();
                                        painter->setBrush(QBrush(QColor((89, 150, 255,1))));
                                        //矩形
                                        //painter->drawRect(allRect.adjusted(0, 0, 0, 0));
                                        //带有弧线矩形
                                        painter->drawRoundedRect(tab->rect, 8, 8);
                                        painter->restore();
                                }
                                //hover状态
                                else if (tab->state & QStyle::State_MouseOver) {
                                        painter->save();
                                        //painter->setBrush(QBrush(0x004ea1));
                                        painter->drawRoundedRect(allRect, 8, 8);
                                        painter->restore();
                                }
                                else {
                                        painter->save();
                                        //painter->setBrush(QBrush(0x78aadc));
                                        painter->drawRoundedRect(allRect, 8, 8);
                                        painter->restore();
                                }
                                QTextOption option;
                                option.setAlignment(Qt::AlignCenter);
                                painter->setFont(QFont("楷体", 12, QFont::Bold));
                                painter->setPen(0xffffff);
                                painter->drawText(allRect, tab->text, option);
                                return;
                        }
                }
                if (element == CE_TabBarTab) {
                        QProxyStyle::drawControl(element, option, painter, widget);
                }
        }
};
// =======================================
// 使用时
        ui->tabWidget->setTabPosition(QTabWidget::West);//QTabWidget竖向
        ui->tabWidget->tabBar()->setStyle(new CustomTabStyle);//注意，设置上述代码风格 就可以实现QTabBar横向

非UI cpp中使用信号槽

1. 两个类必须继承于QObject，同时添加Q_OBJECT。
2. QObject::connect()
   举例: 非ui主函数中关联两个ui
   QObject::connect(pDlg, &QCeC::sig_getFCenter, pTable, &QuiVn::on_sendFCenter);
3. 当前cpp中要加入使用的类声明

-------可能会出现的报错举例-------

1. QT的时候遇到这样一个问题， 简单来说就是一个需要使用信号和槽机制的子类在继承父类并添加 Q_OBJECT 宏之后报这样的错误： ‘staticMetaObject’ is not a member of ‘Manager’
   **解决方法:要自定义信号和槽的话首先你这个类要是一个QObject的子类， 如果需要多继承要将 QObject 放在前面， 同时， 还需要在类声明的开始使用 Q_OBJECT 宏 **
2. connect时如果控件使用了提升类,则需要把对象转换为提升类的指针
   示例:QObject::connect(pDlg, &QTableDlg::send_MVParam, (QJsonTreeBrowser*)CCMain::GetInstance()->GetMainWin()->GetJsonTree(), &QJsonTreeBrowser::getVisionParams);
   其中CCMain::GetInstance()->GetMainWin()->GetJsonTree() 返回QWidget*，而传递信号时需要将其转换为QJsonTreeBrowser* .

// 错误示范
class Controller :
        public AbstractClass, public QObject
{
   ...
//正确示范
class Controller :
        public QObject, public AbstractClass // QObject 写在前面
{
   ...
}

定时器使用

#include <QTimer>

timer = new QTimer(this);
timer->setInterval(100); // 定时间隔
connect(timer, SIGNAL(timeout()), this, SLOT(saveImage())); // 信号槽绑定定时函数
// 打开、关闭定时器
 timer->start();
 timer->stop();

抓取屏幕/指定窗口

QScreen* screen = QApplication::primaryScreen();
QRect rectGif(0, 0, 1000, 900);
// grabWindow 第一个参数是UI窗口控件的id
//QPixmap pix = screen->grabWindow(ui.tab_vision->winId(), ui.tab_vision->x() + rectGif.x(), ui.tab_vision->y() + rectGif.y(), rectGif.width(), rectGif.height());
QPixmap pix = screen->grabWindow(0);//QApplication::desktop()->winId());
QImage image = pix.toImage().convertToFormat(QImage::Format_RGB888);
cv::Mat scr = QImageToCvMat(image);
on_displayImage(scr);

抓取其它应用程序窗口:

//通过spy++.exe 获取(C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Common7\Tools)
#include "WinUser.h"
QString windowname = "WeChat";
QString classname = "Qt5QWindowIcon";
HWND hwnd = FindWindow((LPCWSTR)classname.unicode(), (LPCWSTR)windowname.unicode());//查找窗口句柄
//QString name = "TaskManagerWindow";
//HWND hwnd = FindWindow((LPCWSTR)name.unicode(), L"任务管理器");
//ShowWindow(hwnd, SW_RESTORE);//激活并置顶窗口，ShowWindow里面的参数可以网上搜一下，不同功能不同参数。
QPixmap pix = screen->grabWindow(WId(hwnd)); // WId 获取窗口id

嵌入外部程序窗口进入qt

// 注:有些程序窗口可能会嵌入失败
// 文件管理器嵌入
QString clsname = "CabinetWClass";
QString winname = QStringLiteral("文件资源管理器");
HWND hwnd = FindWindow((LPCWSTR)clsname.unicode(), (LPCWSTR)winname.unicode());
QWindow* pmang = QWindow::fromWinId((WId)hwnd);
//pmang->setFlags(pmang->flags() | Qt::CustomizeWindowHint | Qt::WindowTitleHint);
QWidget* xemb = QWidget::createWindowContainer(pmang, ui.tab_testFilter, Qt::FramelessWindowHint);
xemb->setMinimumSize(900, 800);

QToolBar 如何添加动作图标

需要先在右下角的动作编辑器添加动作，然后将动作选中拖动至ToolBar控件栏 即可
参考 https://blog.csdn.net/Littlehero_121/article/details/129240276