Qt 学习之路 2（18）：事件--代码实现

亦凉 2023-07-01 12:55 5阅读 0赞

## Qt 学习之路 2（18）：事件 ##

在看这个文章的时候完善了作者的代码： \#ifndef EVENTLABEL\_H \#define EVENTLABEL\_H \#include <qmainwindow> \#include <qlabel> class QMouseEvent; class MainWindow : public QMainWindow \{ Q\_OBJECT public: MainWindow(QWidget \*parent = 0); ~MainWindow(); \}; class EventLabel : public QLabel \{ public: EventLabel(QWidget \*parent = 0); ~EventLabel(); protected: void mouseMoveEvent(QMouseEvent \*event); void mousePressEvent(QMouseEvent \*event); void mouseReleaseEvent(QMouseEvent \*event); \}; \#endif // EVENTLABEL\_H \#include "eventlabel.h" \#include <qmouseevent> MainWindow::MainWindow(QWidget \*parent) : QMainWindow(parent) \{ \} MainWindow::~MainWindow() \{ \} void EventLabel::mouseMoveEvent(QMouseEvent \*event) \{ this->setText(QString("<center><h1>Move: (%1, %2)</h1></center>") .arg(QString::number(event->x()), QString::number(event->y()))); \} void EventLabel::mousePressEvent(QMouseEvent \*event) \{ this->setText(QString("<center><h1>Press: (%1, %2)</h1></center>") .arg(QString::number(event->x()), QString::number(event->y()))); \} void EventLabel::mouseReleaseEvent(QMouseEvent \*event) \{ QString msg; msg.sprintf("<center><h1>Release: (%d, %d)</h1></center>", event->x(), event->y()); this->setText(msg); \} EventLabel::EventLabel(QWidget \*parent) : QLabel(parent) \{ \} EventLabel::~EventLabel() \{ \} \#include "eventlabel.h" \#include <qapplication> int main(int argc, char \*argv\[\]) \{ QApplication a(argc, argv); MainWindow w; w.resize(400,300); w.setWindowTitle("MouseEvent Demo"); EventLabel label(&w); //label.setMouseTracking(true); label.resize(300, 200); w.show(); return a.exec(); \} </qapplication></qmouseevent></qlabel></qmainwindow>

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