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1.原理1.1效果2.代码2.1.鼠标事件代码2.2.功能性代码3.注意3.1. 设置Mouse Tracking3.2. 当鼠标在窗口之外如何获取屏幕位置

1.原理

重写GUI类中的鼠标事件的响应函数，并实现其响应函数。

要包含头文件#include <QMouseEvent>

1.1效果

2.代码

2.1.鼠标事件代码

在头文件中声明

protected: //mousevoid mouseMoveEvent(QMouseEvent *event); //移动void mousePressEvent(QMouseEvent *event); //单击void mouseReleaseEvent(QMouseEvent *event);//释放void mouseDoubleClickEvent(QMouseEvent *event); //双击 void wheelEvent(QWheelEvent *event); //滑轮

在源文件中实现

void check_keyboard_mouse::mouseMoveEvent(QMouseEvent *event){//移动QPoint p_ab = event->globalPos();QPoint p_re = event->pos();QString str;str = QString("%1 , %2").arg(p_ab.x()).arg(p_ab.y()); ui.edit_m_absolute->setText(str);str = QString("%1 , %2").arg(p_re.x()).arg(p_re.y());ui.edit_m_relative->setText(str); }void check_keyboard_mouse::mousePressEvent(QMouseEvent *event){//单击// 如果是鼠标左键按下if (event->button() == Qt::LeftButton){//qDebug() << "left click";setMouseState( MouseState::L_C, 0);}// 如果是鼠标右键按下else if (event->button() == Qt::RightButton){//qDebug() << "right click";setMouseState(MouseState::R_C, 0);}else if (event->button() == Qt::MidButton){//qDebug() << "mid click";setMouseState(MouseState::M_C, 0);}}void check_keyboard_mouse::mouseReleaseEvent(QMouseEvent *event){//释放setMouseState(MouseState::Release, 0);}void check_keyboard_mouse::mouseDoubleClickEvent(QMouseEvent *event){//双击// 如果是鼠标左键按下if (event->button() == Qt::LeftButton){//qDebug() << "left double click";setMouseState(MouseState::L_DC, 0);}else if (event->button() == Qt::RightButton){//qDebug() << "right double click";setMouseState(MouseState::R_DC, 0);}}void check_keyboard_mouse::wheelEvent(QWheelEvent *event){//滚轮int wheel_val = event->delta();setMouseState(MouseState::Wheel, wheel_val); // 当滚轮远离使用者时//if (wheel_val > 0){// qDebug() << "wheel forward: " << wheel_val;//}//else{//当滚轮向使用者方向旋转时// qDebug() << "wheel backward: " << wheel_val;//}}

2.2.功能性代码

enum MouseState //自己定义的状态类型{L_C,//left clickR_C,M_C,L_DC,//left double clickR_DC,Wheel,//wheel moveRelease};void check_keyboard_mouse::setMouseState(MouseState ms, int wheelVal){QString style_active = "border:2px solid black;background:green";QString style_release = "border:2px solid black;";setMouseUIdefault();switch (ms){case L_C:ui.lab_mL->setStyleSheet(style_active);break;case R_C:ui.lab_mR->setStyleSheet(style_active);break;case M_C:ui.lab_mM->setStyleSheet(style_active);break;case L_DC:ui.lab_mL_D->setStyleSheet(style_active);break;case R_DC:ui.lab_mR_D->setStyleSheet(style_active);break;case Wheel:ui.lab_mM_val->setText(QString("%1").arg(wheelVal)); if (wheelVal>0){// 当滚轮远离使用者时ui.lab_mM_up->setStyleSheet(style_active);ui.lab_mM_down->setStyleSheet(style_release);} else{ui.lab_mM_up->setStyleSheet(style_release);ui.lab_mM_down->setStyleSheet(style_active);}break; case Release://setMouseUIdefault();break;}}void check_keyboard_mouse::setMouseUIdefault(){QString style_release = "border:2px solid black;";ui.lab_mR_D->setStyleSheet(style_release);ui.lab_mR->setStyleSheet(style_release);ui.lab_mL_D->setStyleSheet(style_release);ui.lab_mL->setStyleSheet(style_release);ui.lab_mM->setStyleSheet(style_release);ui.lab_mM_up->setStyleSheet(style_release);ui.lab_mM_down->setStyleSheet(style_release);}

3.注意

3.1. 设置Mouse Tracking

如果想触发mouseMoveEvent()这个鼠标移动的响应函数，则必须要设置窗体(或控件)是可以Mouse Tracking的，不然程序不会进入mouseMoveEvent()函数。

This property holds whether mouse tracking is enabled for the widget.

If mouse tracking is disabled (the default), the widget only receives mouse move events when at least one mouse button is pressed while the mouse is being moved.

If mouse tracking is enabled, the widget receives mouse move events even if no buttons are pressed.

check_keyboard_mouse::check_keyboard_mouse(QWidget *parent): QDialog(parent){ui.setupUi(this);this->setMouseTracking(true);//设置窗体可响应 Mouse Move ui.edit_m_relative->setMouseTracking(true);//控件1ui.edit_m_absolute->setMouseTracking(true);//控件2ui.edit_keyValue->setMouseTracking(true);//控件3ui.edit_keyValue_Hex->setMouseTracking(true);//控件4ui.edit_keyValue_QtKey->setMouseTracking(true);//控件5}

3.2. 当鼠标在窗口之外如何获取屏幕位置

当鼠标移动出窗体，鼠标就无法进入mouseMoveEvent()函数，此时就需要通过其他方式获取鼠标在屏幕上的位置信息。

这里用到了这个QCursor类，这个类中有一个获取鼠标当前屏幕位置(绝对位置)的一个静态方法。

static QPoint QCursor::pos(const QScreen * screen)

我在这里的处理方式是，通过按键盘的Ctrl键，获取当前的鼠标的绝对位置，需要实现键盘的按键响应函数，已经在之前的博客中写到。

void check_keyboard_mouse::keyPressEvent(QKeyEvent *event){qDebug() << "=== press key";int keyValue = event->key();if (keyValue == Qt::Key_Control){//获取鼠标位置QPoint pt = QCursor::pos();//获取鼠标的绝对位置QString str;str = QString("%1 , %2").arg(pt.x()).arg(pt.y()); ui.edit_m_absolute->setText(str);//显示} }