用QT编写一个简单的鼠绘程序，只要求能画出线条，该怎么实现程序对鼠标动作的响应呢？

发布网友发布时间：2022-05-23 14:39

共1个回答

热心网友时间：2023-10-25 11:31

#ifndef MYWIDGET_H
#define MYWIDGET_H

#include <QWidget>
#include <QtGui>
#include <QMouseEvent>

class MyWidget : public QWidget
{
public:
    MyWidget();
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
    void mouseReleaseEvent(QMouseEvent *event);
    void paintEvent(QPaintEvent *event);

private:
    QPoint m_PointStart;
    QPoint m_PointEnd;
};

#endif // MYWIDGET_H
#include <QtGui/QApplication>
#include "mainwindow.h"

#include "mywidget.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MyWidget widget;
    widget.show();

    return a.exec();
}
#include "mywidget.h"

MyWidget::MyWidget()
{
    resize(240,320);
}

void MyWidget::mousePressEvent(QMouseEvent *event)
{
    m_PointStart = event->pos();

}

void MyWidget::mouseMoveEvent(QMouseEvent *event)
{
    //m_PointEnd = event->pos();
   //update();
}

void MyWidget::mouseReleaseEvent(QMouseEvent *event)
{
    m_PointEnd = event->pos();
    update();
}

void MyWidget::paintEvent(QPaintEvent *event)
{
    QPainter painter(this);
    painter.setBrush(QBrush(QColor(255,0,0)));
    painter.drawPixmap(0,0,240,320,QPixmap("images/frame1.jpg"));

    if(m_PointStart.x() < m_PointEnd.x())
        painter.drawPixmap(0,0,240,320,QPixmap("images/frame2.jpg"));
    else if(m_PointStart.x() > m_PointEnd.x())
        painter.drawPixmap(0,0,240,320,QPixmap("images/frame3.jpg"));

}

在网上找到了一个很好的类子，一看就明白

转自：http://www.cppblog.com/qianqian/archive/2012/05/21/121418.html