QT事件、事件过滤、自定义事件练习

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我是靠谱客的博主生动往事，最近开发中收集的这篇文章主要介绍QT事件、事件过滤、自定义事件练习，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

EventLabel.h


#pragma once

#include <QLabel>

class EventLabel :
	public QLabel
{
public:
	EventLabel();
	~EventLabel();

protected:
	void mouseMoveEvent(QMouseEvent *event);
	void mousePressEvent(QMouseEvent *event);
	void mouseReleaseEvent(QMouseEvent *event);

	bool event(QEvent *e);
};


EventLabel.cpp


#include "EventLabel.h"
#include <QMouseEvent>
#include "ChangeNumberEvent.h"


EventLabel::EventLabel()
{
}


EventLabel::~EventLabel()
{
}

void EventLabel::mouseMoveEvent(QMouseEvent * event1)
{
	QString msg;
	msg.sprintf("<center><h1>Move: (%d, %d)</h1></center>",
		event1->x(), event1->y());
	this->setText(msg);
}

void EventLabel::mousePressEvent(QMouseEvent * event)
{
	QString msg;
	msg.sprintf("<center><h1>Press: (%d, %d)</h1></center>",
		event->x(), event->y());
	this->setText(msg);
}

void EventLabel::mouseReleaseEvent(QMouseEvent * event)
{
	QString msg;
	msg.sprintf("<center><h1>Release: (%d, %d)</h1></center>",
		event->x(), event->y());
	this->setText(msg);
}

bool EventLabel::event(QEvent * e)
{
	if (e->type() == QEvent::KeyPress) {
		QKeyEvent *keyEvent = static_cast<QKeyEvent *>(e);
		if (keyEvent->key() == Qt::Key_Tab) {
			QString msg;
			msg.sprintf("<center><h1>event: (%d, %d)</h1></center>");
			this->setText(msg);
			return true;
		}
	}
	return QWidget::event(e);
}

ChangeNumberEvent.h

#pragma once
#include <qcoreevent.h>
#include <QString>
class ChangeNumberEvent :
	public QEvent
{
public:
	ChangeNumberEvent(QObject* parent, QString number);
	~ChangeNumberEvent();

public:
	QString m_Number;
};


ChangeNumberEvent.cpp


#include "ChangeNumberEvent.h"


//自定义事件ID
//自定义事件ID范围是从QEvent::User(1000)到QEvent::MaxUser(65535)
//可以通过在前一次自定义事件ID的基础上加一的方式定义所有的自定义事件ID
const int CustomEventBaseID = QEvent::User;
const int ChangeNumberEventID = CustomEventBaseID + 1;


ChangeNumberEvent::ChangeNumberEvent(QObject* parent, QString number)
	:QEvent(QEvent::Type(ChangeNumberEventID)),
	m_Number(number)
{
}


ChangeNumberEvent::~ChangeNumberEvent()
{
}

QT_Test.h

#pragma once

#include <QtWidgets/QDialog>
#include "ui_QT_Test.h"

class QT_Test : public QDialog
{
	Q_OBJECT

public:
	QT_Test(QApplication* pApp, QWidget *parent = Q_NULLPTR);
	//(QApplication* pApp, QWidget *parent = Q_NULLPTR);

protected:
	bool eventFilter(QObject *watched, QEvent *event);
	void customEvent(QEvent *event);

public slots:
	void onClickButton1();
private:
	Ui::QT_TestClass ui;
	QApplication* m_pApp = nullptr;
};

QT_Test.cpp


#include "QT_Test.h"
#include <QFileDialog.h>
#include <qstring.h>
#include "EventLabel.h"
#include <QMouseEvent>
#include "ChangeNumberEvent.h"

QT_Test::QT_Test(QApplication* pApp, QWidget *parent)
	: QDialog(parent)
	, m_pApp(pApp)
{
	ui.setupUi(this);

	connect(ui.btn1, SIGNAL(clicked()), this, SLOT(onClickButton1()));
}

void QT_Test::onClickButton1()
{

	//发送事件
	QString curNumber = ui.edit1->text();// spinBox->value();
	ChangeNumberEvent e(this, curNumber);
	m_pApp->sendEvent(this, &e);


	EventLabel *label = new EventLabel;
	label->setWindowTitle("MouseEvent Demo");
	label->installEventFilter(this);
	label->resize(300, 200);
	label->show();
}

bool QT_Test::eventFilter(QObject * watched, QEvent * event)
{
	//object == target && 
	if (event->type() == QEvent::KeyPress) {
		QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
			if (keyEvent->key() == Qt::Key_Tab) {
			QString msg;
			msg.sprintf("<center><h1>event: (%d, %d)</h1></center>");
		//	this->setText(msg);
			return true;
		}
		else {
				return false;
		}
	}
	return QDialog::eventFilter(watched, event);
	
}

void QT_Test::customEvent(QEvent * event)
{
	//ChangeNumberEvent* e = dynamic_cast<ChangeNumberEvent*>(event);
	//if (e)
	//{
	//	ui.la1->setText(e->m_Number);
	//	ui.la2->setText(e->m_Number);
	//}
}