教你做企业网站,个人网站可以备案了吗,wordpress 全局tag,网站建设读书笔记文章目录 事件过滤完整代码 事件过滤
事件过滤是当事件发生时#xff0c;可以对不同对象#xff0c;实现不同操作#xff0c;以达到筛选的效果。 步骤#xff1a; 1、首先安装一个事件过滤器#xff0c;为对象安装事件过滤#xff0c;指定“谁”来监控这些事件对象
//给… 文章目录 事件过滤完整代码 事件过滤
事件过滤是当事件发生时可以对不同对象实现不同操作以达到筛选的效果。 步骤 1、首先安装一个事件过滤器为对象安装事件过滤指定“谁”来监控这些事件对象
//给m_label123安装事件过滤指定(this)当前整个窗体监视我们的事件对象
m_label1-installEventFilter(this);
m_label2-installEventFilter(this);
m_label3-installEventFilter(this);2、重写bool eventFilter(QObject *obj, QEvent *event)。
//第一个参数是监视对象第二个参数是事件
bool EventFilter::eventFilter(QObject *watched, QEvent *event)
{QMatrix matrix;QImage tmpImg;//放大图片matrix.scale(2.0,2.0);if(watched m_label1){//鼠标按下事件if(event-type() QEvent::MouseButtonPress){QMouseEvent* mouseEvent (QMouseEvent*)event;if(mouseEvent-buttons()Qt::LeftButton){m_stateLabel-setText(QStringLiteral(左键按下图片1));}if(mouseEvent-buttons()Qt::MidButton){m_stateLabel-setText(QStringLiteral(中键按下图片1));}if(mouseEvent-buttons()Qt::RightButton){m_stateLabel-setText(QStringLiteral(右键按下图片1));}tmpImg m_image1.transformed(matrix);m_label1-setPixmap(QPixmap::fromImage(tmpImg));}if(event-type()QEvent::MouseButtonRelease){m_stateLabel-setText(QStringLiteral(鼠标释放图片1));m_label1-setPixmap(QPixmap::fromImage(m_image1));}}else if(watched m_label2){//鼠标按下事件if(event-type() QEvent::MouseButtonPress){QMouseEvent* mouseEvent (QMouseEvent*)event;if(mouseEvent-buttons()Qt::LeftButton){m_stateLabel-setText(QStringLiteral(左键按下图片2));}if(mouseEvent-buttons()Qt::MidButton){m_stateLabel-setText(QString(中键按下图片2));}if(mouseEvent-buttons()Qt::RightButton){m_stateLabel-setText(QString(右键按下图片2));}tmpImg m_image2.transformed(matrix);m_label2-setPixmap(QPixmap::fromImage(tmpImg));}if(event-type()QEvent::MouseButtonRelease){m_stateLabel-setText(QStringLiteral(鼠标释放图片2));m_label2-setPixmap(QPixmap::fromImage(m_image2));}}else if(watched m_label3){//鼠标按下事件if(event-type() QEvent::MouseButtonPress){QMouseEvent* mouseEvent (QMouseEvent*)event;if(mouseEvent-buttons()Qt::LeftButton){m_stateLabel-setText(QStringLiteral(左键按下图片3));}if(mouseEvent-buttons()Qt::MidButton){m_stateLabel-setText(QStringLiteral(中键按下图片3));}if(mouseEvent-buttons()Qt::RightButton){m_stateLabel-setText(QStringLiteral(右键按下图片3));}tmpImg m_image3.transformed(matrix);m_label3-setPixmap(QPixmap::fromImage(tmpImg));}if(event-type()QEvent::MouseButtonRelease){m_stateLabel-setText(QStringLiteral(鼠标释放图片3));m_label3-setPixmap(QPixmap::fromImage(m_image3));}}//将事件交给上层对话框进行处理return QDialog::eventFilter(watched,event);
}
完整代码
eventfilter.h
#ifndef EVENTFILTER_H
#define EVENTFILTER_H#include QDialog
#include QLabel
class EventFilter : public QDialog
{Q_OBJECTpublic:EventFilter(QWidget *parent 0,Qt::WindowFlags f 0);~EventFilter();
public slots://第一个参数是监视的对象第二个参数是事件bool eventFilter(QObject*watched,QEvent *event)override;
private://将图片加载到label中QLabel* m_label1;QLabel* m_label2;QLabel* m_label3;QLabel* m_stateLabel;//QImage m_image1;QImage m_image2;QImage m_image3;
};#endif // EVENTFILTER_H
eventfilter.cpp
#include eventfilter.h
#include QPixmap
#include QHBoxLayout
#include QVBoxLayout
#include QEvent
#include QMouseEvent
EventFilter::EventFilter(QWidget *parent,Qt::WindowFlags f): QDialog(parent,f)
{setWindowTitle(QStringLiteral(事件过滤));m_label1 new QLabel;m_label2 new QLabel;m_label3 new QLabel;m_stateLabel new QLabel(QStringLiteral(鼠标按下标志));//加个框框//m_stateLabel-setFrameStyle(QFrame::Box);//设置对齐方式水平居中m_stateLabel-setAlignment(Qt::AlignHCenter);m_image1.load(./fly1.png);m_image2.load(./fly2.png);m_image3.load(./fly3.png);m_label1-setPixmap(QPixmap::fromImage(m_image1));m_label2-setPixmap(QPixmap::fromImage(m_image2));m_label3-setPixmap(QPixmap::fromImage(m_image3));QHBoxLayout* layout new QHBoxLayout;layout-addWidget(m_label1);layout-addWidget(m_label2);layout-addWidget(m_label3);QVBoxLayout* mainLayout new QVBoxLayout(this);mainLayout-addLayout(layout);mainLayout-addWidget(m_stateLabel);resize(m_image2.width() * 3,m_image2.height() * 2);//给m_label123安装事件过滤指定(this)当前整个窗体监视我们的事件对象m_label1-installEventFilter(this);m_label2-installEventFilter(this);m_label3-installEventFilter(this);}EventFilter::~EventFilter()
{}
//第一个参数是监视对象第二个参数是事件
bool EventFilter::eventFilter(QObject *watched, QEvent *event)
{QMatrix matrix;QImage tmpImg;//放大图片matrix.scale(2.0,2.0);if(watched m_label1){//鼠标按下事件if(event-type() QEvent::MouseButtonPress){QMouseEvent* mouseEvent (QMouseEvent*)event;if(mouseEvent-buttons()Qt::LeftButton){m_stateLabel-setText(QStringLiteral(左键按下图片1));}if(mouseEvent-buttons()Qt::MidButton){m_stateLabel-setText(QStringLiteral(中键按下图片1));}if(mouseEvent-buttons()Qt::RightButton){m_stateLabel-setText(QStringLiteral(右键按下图片1));}tmpImg m_image1.transformed(matrix);m_label1-setPixmap(QPixmap::fromImage(tmpImg));}if(event-type()QEvent::MouseButtonRelease){m_stateLabel-setText(QStringLiteral(鼠标释放图片1));m_label1-setPixmap(QPixmap::fromImage(m_image1));}}else if(watched m_label2){//鼠标按下事件if(event-type() QEvent::MouseButtonPress){QMouseEvent* mouseEvent (QMouseEvent*)event;if(mouseEvent-buttons()Qt::LeftButton){m_stateLabel-setText(QStringLiteral(左键按下图片2));}if(mouseEvent-buttons()Qt::MidButton){m_stateLabel-setText(QString(中键按下图片2));}if(mouseEvent-buttons()Qt::RightButton){m_stateLabel-setText(QString(右键按下图片2));}tmpImg m_image2.transformed(matrix);m_label2-setPixmap(QPixmap::fromImage(tmpImg));}if(event-type()QEvent::MouseButtonRelease){m_stateLabel-setText(QStringLiteral(鼠标释放图片2));m_label2-setPixmap(QPixmap::fromImage(m_image2));}}else if(watched m_label3){//鼠标按下事件if(event-type() QEvent::MouseButtonPress){QMouseEvent* mouseEvent (QMouseEvent*)event;if(mouseEvent-buttons()Qt::LeftButton){m_stateLabel-setText(QStringLiteral(左键按下图片3));}if(mouseEvent-buttons()Qt::MidButton){m_stateLabel-setText(QStringLiteral(中键按下图片3));}if(mouseEvent-buttons()Qt::RightButton){m_stateLabel-setText(QStringLiteral(右键按下图片3));}tmpImg m_image3.transformed(matrix);m_label3-setPixmap(QPixmap::fromImage(tmpImg));}if(event-type()QEvent::MouseButtonRelease){m_stateLabel-setText(QStringLiteral(鼠标释放图片3));m_label3-setPixmap(QPixmap::fromImage(m_image3));}}//将事件交给上层对话框进行处理return QDialog::eventFilter(watched,event);
}
运行效果
