Qt5开发及实例-CH1103.rar,Qt5通过事件过滤器实现动态图片按钮效果的代码

#include "eventfilter.h" #include <QHBoxLayout> #include <QVBoxLayout> #include <QMouseEvent> #include <QMatrix> EventFilter::EventFilter(QWidget *parent,Qt::WindowFlags f) : QDialog(parent,f) { setWindowTitle(tr("事件过滤")); label1 = new QLabel; Image1.load("../image/1.png"); label1->setAlignment(Qt::AlignHCenter|Qt::AlignVCenter); label1->setPixmap(QPixmap::fromImage(Image1)); label2 = new QLabel; Image2.load("../image/2.png"); label2->setAlignment(Qt::AlignHCenter|Qt::AlignVCenter); label2->setPixmap(QPixmap::fromImage(Image2)); label3 = new QLabel; Image3.load("../image/3.png"); label3->setAlignment(Qt::AlignHCenter|Qt::AlignVCenter); label3->setPixmap(QPixmap::fromImage(Image3)); stateLabel = new QLabel(tr("鼠标按下标志")); stateLabel->setAlignment(Qt::AlignHCenter); QHBoxLayout *layout=new QHBoxLayout; layout->addWidget(label1); layout->addWidget(label2); layout->addWidget(label3); QVBoxLayout *mainLayout = new QVBoxLayout(this); mainLayout->addLayout(layout); mainLayout->addWidget(stateLabel); label1->installEventFilter(this); label2->installEventFilter(this); label3->installEventFilter(this); } bool EventFilter::eventFilter(QObject *watched, QEvent *event) { if(watched==label1) //首先判断当前发生事件的对象 { //判断发生的事件类型 if(event->type()==QEvent::MouseButtonPress) { //将事件event转化为鼠标事件 QMouseEvent *mouseEvent=(QMouseEvent *)event; /* 以下根据鼠标的按键类型分别显示 */ if(mouseEvent->buttons()&Qt::LeftButton) { stateLabel->setText(tr("左键按下左边图片")); } else if(mouseEvent->buttons()&Qt::MidButton) { stateLabel->setText(tr("中键按下左边图片")); } else if(mouseEvent->buttons()&Qt::RightButton) { stateLabel->setText(tr("右键按下左边图片")); } /* 显示缩小的图片 */ QMatrix matrix; matrix.scale(1.8,1.8); QImage tmpImg=Image1.transformed(matrix); label1->setPixmap(QPixmap::fromImage(tmpImg)); } /* 鼠标释放事件的处理，恢复图片的大小 */ if(event->type()==QEvent::MouseButtonRelease) { stateLabel->setText(tr("鼠标释放左边图片")); label1->setPixmap(QPixmap::fromImage(Image1)); } } else if(watched==label2) { if(event->type()==QEvent::MouseButtonPress) { //将事件event转化为鼠标事件 QMouseEvent *mouseEvent=(QMouseEvent *)event; /* 以下根据鼠标的按键类型分别显示 */ if(mouseEvent->buttons()&Qt::LeftButton) { stateLabel->setText(tr("左键按下中间图片")); } else if(mouseEvent->buttons()&Qt::MidButton) { stateLabel->setText(tr("中键按下中间图片")); } else if(mouseEvent->buttons()&Qt::RightButton) { stateLabel->setText(tr("右键按下中间图片")); } /* 显示缩小的图片 */ QMatrix matrix; matrix.scale(1.8,1.8); QImage tmpImg=Image2.transformed(matrix); label2->setPixmap(QPixmap::fromImage(tmpImg)); } /* 鼠标释放事件的处理，恢复图片的大小 */ if(event->type()==QEvent::MouseButtonRelease) { stateLabel->setText(tr("鼠标释放中间图片")); label2->setPixmap(QPixmap::fromImage(Image2)); } } else if(watched==label3) { if(event->type()==QEvent::MouseButtonPress) { //将事件event转化为鼠标事件 QMouseEvent *mouseEvent=(QMouseEvent *)event; /* 以下根据鼠标的按键类型分别显示 */ if(mouseEvent->buttons()&Qt::LeftButton) { stateLabel->setText(tr("左键按下右边图片")); } else if(mouseEvent->buttons()&Qt::MidButton) { stateLabel->setText(tr("中键按下右边图片")); } else if(mouseEvent->buttons()&Qt::RightButton) { stateLabel->setText(tr("右键按下右边图片")); } /* 显示缩小的图片 */ QMatrix matrix; matrix.scale(1.8,1.8); QImage tmpImg=Image3.transformed(matrix); label3->setPixmap(QPixmap::fromImage(tmpImg)); } /* 鼠标释放事件的处理，恢复图片的大小 */ if(event->type()==QEvent::MouseButtonRelease) { stateLabel->setText(tr("鼠标释放右边图片")); label3->setPixmap(QPixmap::fromImage(Image3)); } } //将事件交给上层对话框 return QDialog::eventFilter(watched,event); } EventFilter::~EventFilter() { }