QT中鼠标事件解析

　　以前在Linux下写过关于鼠标的应用程序，通过read系统调用去读取/dev/input/mice设备节点数据，然后做一些数据相关的处理，然后显示鼠标光标等，这里就牵扯到一些图片相关的算法了，比如图像的缩放，合并。自从开始学C++和QT后才发现以前真的是瞎折腾，什么自己造*。ＱＴ类已经帮你做好这一切了，只需要去调用类就行。

　　ＱＴ中关于鼠标的类是QMouseEvent，我们在设计界面上添加一个Text Edit。用来作为输入。鼠标中常用的事件有：

    void mousePressEvent(QMouseEvent *event);
    void mouseReleaseEvent(QMouseEvent *event);
    void mouseDoubleClickEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
    void wheelEvent(QWheelEvent *event);

这些函数只看函数名大家也应该知道其作用是什么了，下面是我的代码：代码相对比较简单，我就不做过多的介绍了，代码的作用是方便读者怎么去使用鼠标类的接口，可以当做是笔记吧。

main.cpp

#include <QtGui/QApplication>#include "widget.h"

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

    return a.exec();
}

widget.h

#ifndef WIDGET_H#define WIDGET_H#include <QWidget>#include <QMouseEvent>namespace Ui {class Widget;}class Widget : public QWidget{    Q_OBJECT    public:    explicit Widget(QWidget *parent = 0);    ~Widget();    private:    Ui::Widget *ui;    QPoint offset;protected:    void mousePressEvent(QMouseEvent *event);    void mouseReleaseEvent(QMouseEvent *event);    void mouseDoubleClickEvent(QMouseEvent *event);    void mouseMoveEvent(QMouseEvent *event);    void wheelEvent(QWheelEvent *event);};#endif // WIDGET_H

widget.cpp

#include "widget.h"#include "ui_widget.h"Widget::Widget(QWidget *parent) :    QWidget(parent),    ui(new Ui::Widget){    ui->setupUi(this);    QCursor cursor;    cursor.setShape(Qt::OpenHandCursor);    setCursor(cursor);}Widget::~Widget(){    delete ui;}void Widget::mousePressEvent(QMouseEvent *event){    if(event->button() == Qt::LeftButton){        QCursor cursor;        cursor.setShape(Qt::ClosedHandCursor);        QApplication::setOverrideCursor(cursor);        offset = event->globalPos() - pos();    }    else if(event->button() == Qt::RightButton)    {        QCursor cursor(QPixmap("../mouse.png"));        QApplication::setOverrideCursor(cursor);    }}void Widget::mouseMoveEvent(QMouseEvent *event){    if(event->buttons() & Qt::LeftButton)    {        QPoint temp;        temp = event->globalPos() - offset;        move(temp);    }}void Widget::mouseReleaseEvent(QMouseEvent *event){    QApplication::restoreOverrideCursor();}void Widget::mouseDoubleClickEvent(QMouseEvent *event){    if(event->button() == Qt::LeftButton)    {        if(windowState() != Qt::WindowFullScreen)            setWindowState(Qt::WindowFullScreen);        else            setWindowState(Qt::WindowNoState);    }}void Widget::wheelEvent(QWheelEvent *event){    if(event->delta() > 0){        ui->textEdit->zoomIn();    }else{        ui->textEdit->zoomOut();    }}

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QT中鼠标事件解析

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