Qt5_在QWidget中画动态图（）转

在以前的文章中，我们介绍了如何在QTabWidget中画网络拓扑图。今天，我们介绍一下，如何使得所画的图呈现出动态的变化，比如在网络拓扑中，随着时间的变化，一些节点显示红色，一些节点显示绿色。
准备过程：红色和绿色的图片
思路：依旧使用重写paintevent函数来实现画图功能，要使图片随着时间的变化更新，就需要使用计时器来触发页面更新，页面更新可以使用update函数。
代码：

#include "showtopology.h"
#include "mainwindow.h"
#include <QPainter>
#include <QWidget>
#include <QTime>
#include <QTimer>


showtopology::showtopology(QWidget *parent) : QWidget(parent)
{
    QTimer *timer3= new QTimer();//声明计时器
    connect(timer3,SIGNAL(timeout()),this,SLOT(update()));//计时器用来触发更新
    timer3->start(1000);//更新间隔为1秒
}
void showtopology::paintEvent(QPaintEvent *event)
{
    QPainter paint(this);
    paint.setPen(Qt::DashLine);
    paint.setRenderHint(QPainter::Antialiasing, true);
    QPixmap ap1("ap1.png");//AP和两种STA的图片的声明；
    QPixmap img1("STA2.png");
    QPixmap img2("STA1.png");
    paint.drawPixmap(350,150,ap1);

    qsrand(time(NULL));
    int n1;
    double n[50];//一共有50个节点
    for (int i =0; i<50; i++)
        {
        n1= qrand();
        n[i] = n1/10000000.0;
    }
    for(int i = 0; i<50; i++)
        {
        if (n[i]<30)//使某一个节点的随机数小于30的显示STA2的图片
            {
            switch (i)
                    {
                case 0 :paint.drawPixmap(50,20,img1);
                    break;
                case 1: paint.drawPixmap(100,100,img1);
                    break;
                case 2:  paint.drawPixmap(350,200,img1);
                    break;
                case 3: paint.drawPixmap(500,200,img1);
                    break;
                case 4 :paint.drawPixmap(300,75,img1);
                    break;
                case 5 :paint.drawPixmap(503,120,img1);
                    break;
                case 6 :paint.drawPixmap(160,66,img1);
                    break;
                case 7 :paint.drawPixmap(200,190,img1);
                    break;
                case 8: paint.drawPixmap(360,190,img1);
                    break;
                case 9 :paint.drawPixmap(350,180,img1);
                    break;
                default : break;
            }
            paint.drawLine(350,150,50,20);
            paint.drawLine(350,150,100,100);
            paint.drawLine(350,150,350,200);
            paint.drawLine(350,150,500,200);
            paint.drawLine(350,150,300,75);
            paint.drawLine(350,150,503,120);
            paint.drawLine(350,150,160,66);
            paint.drawLine(350,150,200,190);
            paint.drawLine(350,150,360,190);
            paint.drawLine(350,150,350,180);
        }
        else//节点随机数大于30的显示STA1的图片
        {
            switch (i)
                    {
                case 0 :paint.drawPixmap(50,20,img2);//画STA
                    break;
                case 1: paint.drawPixmap(100,100,img2);
                    break;
                case 2:  paint.drawPixmap(350,200,img2);
                    break;
                case 3: paint.drawPixmap(500,200,img2);
                    break;
                case 4 :paint.drawPixmap(300,75,img2);
                    break;
                case 5 :paint.drawPixmap(503,120,img2);
                    break;
                case 6 :paint.drawPixmap(160,66,img2);
                    break;
                case 7 :paint.drawPixmap(200,190,img2);
                    break;
                case 8: paint.drawPixmap(360,190,img2);
                    break;
                case 9 :paint.drawPixmap(350,180,img2);
                    break;
                default : break;
            }
        paint.drawLine(350,150,50,20);//画连接线
        paint.drawLine(350,150,100,100);
        paint.drawLine(350,150,350,200);
        paint.drawLine(350,150,500,200);
        paint.drawLine(350,150,300,75);
        paint.drawLine(350,150,503,120);
        paint.drawLine(350,150,160,66);
        paint.drawLine(350,150,200,190);
        paint.drawLine(350,150,360,190);
        paint.drawLine(350,150,350,180);
        }
    }
}

最终的效果如下图所示：

 

 

 

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版权声明：本文为CSDN博主「caoyangxiaoyao」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/caoyangxiaoyao/article/details/69261265