QT5基于QTimer定时器和QPainter绘制动态图像的学习ui大糊涂虫-

效果图：

目录结构：

头文件：

 #ifndef MYWIDGET_H #define MYWIDGET_H  #include <QMainWindow>  namespace Ui { class MyWidget; }  class MyWidget : public QMainWindow {     Q_OBJECT  public:     explicit MyWidget(QWidget *parent = 0);     ~MyWidget();      void paintEvent(QPaintEvent *event);   private:     Ui::MyWidget *ui;    int crossCenterX;    int crossCenterY;    QTimer *timer;    int step;    bool isReverse; };  #endif // MYWIDGET_H 

源文件：

 #include "mywidget.h" #include "ui_mywidget.h" #include <QPainter> #include <QTimer> MyWidget::MyWidget(QWidget *parent) :     QMainWindow(parent),     ui(new Ui::MyWidget) {     ui->setupUi(this);     //设置窗体的大小     this->resize(512,512);     //设置中心点的坐标，保存为变量     crossCenterX=this->width()/2;     crossCenterY=this->height()/2;     //设置定时器，时间间隔围为80ms     timer=new QTimer(this);     step=-100;     isReverse=false;     //设置定时触发信号，在定时信号处理的槽函数中，判断当前的偏移量是否够在±100范围内     //当超出边界范围时，改变方向标记h     connect(timer,&QTimer::timeout,[=](){         if(step>100){             isReverse=true;         }else if(step<-100) {             isReverse=false;         }         update();     });     timer->setInterval(80);     timer->start();  }  MyWidget::~MyWidget() {     delete ui; } void MyWidget::paintEvent(QPaintEvent *event){     QPainter painter(this);     painter.setBrush(Qt::black);     painter.drawRect(rect());     painter.setPen(Qt::white);     //绘制文字     QFont font;     font.setPointSize(20);     painter.setFont(font);     painter.drawText(20,40,"TV");     //绘制右下角图片     painter.drawPixmap(this->width()-128,this->height()-128,128,128,QPixmap(":/Images/test.png"));     //水平线     painter.drawLine(QPoint(crossCenterX-256/2+step,crossCenterY),QPoint(crossCenterX+256/2+step,crossCenterY));     painter.drawLine(QPoint(crossCenterX+step,crossCenterY-256/2),QPoint(crossCenterX+step,crossCenterY+256/2));     if(!isReverse) {         step+=3;//向正方向运行     }else{         step-=3;//向反方向运行     }   } 

搜素：TestWidget.zip可以找到资源