修改QLabel使QLabel支持鼠标事件

分类：Others, Qt 阅读 (2,778) Add comments

1月 272019

转载请注明原文地址：http://bcoder.com/others/modify-qlabel-to-support-mouse-event

　　QLabel并不支持鼠标按下、松开等事件，我们需要新建一个QLabel的子类来支持。

　　编写qadvancedlabel.h

#ifndef QADVANCEDLABEL_H
#define QADVANCEDLABEL_H

#include <QLabel>

class QAdvancedLabel : public QLabel
{
    Q_OBJECT

public:
    QAdvancedLabel(QWidget *parent = nullptr);

protected:
    virtual void mousePressEvent(QMouseEvent *event);    //鼠标按下
    virtual void mouseReleaseEvent(QMouseEvent *event);  //鼠标松开
    virtual void mouseDoubleClickEvent(QMouseEvent *event);  //双击鼠标
    virtual void mouseMoveEvent(QMouseEvent *event);     //鼠标移动

signals:
    void pressed(QMouseEvent *event);  //鼠标按下
    void clicked(QMouseEvent *event);  //鼠标松开
    void doubled(QMouseEvent *event);  //双击鼠标
    void moved(QMouseEvent *event);    //鼠标移动

public slots:
};

#endif // QADVANCEDLABEL_H

#ifndef QADVANCEDLABEL_H

#define QADVANCEDLABEL_H

#include <QLabel>

class QAdvancedLabel : public QLabel

{

Q_OBJECT

public:

QAdvancedLabel(QWidget *parent = nullptr);

protected:

virtual void mousePressEvent(QMouseEvent *event); //鼠标按下

virtual void mouseReleaseEvent(QMouseEvent *event); //鼠标松开

virtual void mouseDoubleClickEvent(QMouseEvent *event); //双击鼠标

virtual void mouseMoveEvent(QMouseEvent *event); //鼠标移动

signals:

void pressed(QMouseEvent *event); //鼠标按下

void clicked(QMouseEvent *event); //鼠标松开

void doubled(QMouseEvent *event); //双击鼠标

void moved(QMouseEvent *event); //鼠标移动

public slots:

};

#endif // QADVANCEDLABEL_H

　　然后增加QAdvancedLabel的cpp文件，qadvancedlabel.cpp

#include "include/qadvancedlabel.h"

QAdvancedLabel::QAdvancedLabel(QWidget *parent) : QLabel(parent)
{
}


void QAdvancedLabel::mousePressEvent(QMouseEvent *event)
{
    emit pressed(event);
}

void QAdvancedLabel::mouseReleaseEvent(QMouseEvent *event)
{
    emit clicked(event);
}

void QAdvancedLabel::mouseDoubleClickEvent(QMouseEvent *event)
{
    emit doubled(event);
}

void QAdvancedLabel::mouseMoveEvent(QMouseEvent *event)
{
    emit moved(event);
}

#include "include/qadvancedlabel.h"

QAdvancedLabel::QAdvancedLabel(QWidget *parent) : QLabel(parent)

{

}

void QAdvancedLabel::mousePressEvent(QMouseEvent *event)

{

emit pressed(event);

}

void QAdvancedLabel::mouseReleaseEvent(QMouseEvent *event)

{

emit clicked(event);

}

void QAdvancedLabel::mouseDoubleClickEvent(QMouseEvent *event)

{

emit doubled(event);

}

void QAdvancedLabel::mouseMoveEvent(QMouseEvent *event)

{

emit moved(event);

}

　　然后在程序中的实现：

　　mainwindow.h文件

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QObject>
#include <QMainWindow>
#include <QMouseEvent>

#include "qadvancedlabel.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT


public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private slots:
    void onQAdvLabelMouseEvent(QMouseEvent *event);

private:
    Ui::MainWindow *ui;
    QAdvancedLabel *testQAdvLabel;

};

#endif // MAINWINDOW_H

#ifndef MAINWINDOW_H

#define MAINWINDOW_H

#include <QObject>

#include <QMainWindow>

#include <QMouseEvent>

#include "qadvancedlabel.h"

namespace Ui {

class MainWindow;

}

class MainWindow : public QMainWindow

{

Q_OBJECT

public:

explicit MainWindow(QWidget *parent = 0);

~MainWindow();

private slots:

void onQAdvLabelMouseEvent(QMouseEvent *event);

private:

Ui::MainWindow *ui;

QAdvancedLabel *testQAdvLabel;

};

#endif // MAINWINDOW_H

　　mainwindow.cpp文件

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    testQAdvLabel = new QAdvancedLabel(ui->centralWidget);
    testQAdvLabel->setText("test mouse move");
    connect(testQAdvLabel, SIGNAL(moved(QMouseEvent*)), this, SLOT(onQAdvLabelMouseEvent(QMouseEvent*)));

    testQAdvLabel->setMouseTracking(true);
}

void MainWindow::onQAdvLabelMouseEvent(QMouseEvent *event)
{
    qDebug("x: %d, y: %d", event->x(), event->y());
}

MainWindow::MainWindow(QWidget *parent) :

QMainWindow(parent),

ui(new Ui::MainWindow)

{

ui->setupUi(this);

testQAdvLabel = new QAdvancedLabel(ui->centralWidget);

testQAdvLabel->setText("test mouse move");

connect(testQAdvLabel, SIGNAL(moved(QMouseEvent*)), this, SLOT(onQAdvLabelMouseEvent(QMouseEvent*)));

testQAdvLabel->setMouseTracking(true);

}

void MainWindow::onQAdvLabelMouseEvent(QMouseEvent *event)

{

qDebug("x: %d, y: %d", event->x(), event->y());

}

　　记得一定要设置setMouseTracking，否则只有按下时才会响应move事件。

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记得一定要设置setMouseTracking，否则只有按下时才会响应move事件。

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　　记得一定要设置setMouseTracking，否则只有按下时才会响应move事件。