使用QT实现倒计时——20191103

1、界面如下：

2、实现代码：QTime_Show2.h

#ifndef QTIME_SHOW2_H
#define QTIME_SHOW2_H

#include <QtGui/QMainWindow>
#include "ui_qtime_show2.h"

class QTime_Show2 : public QMainWindow
{
	Q_OBJECT

public:
	QTime_Show2(QWidget *parent = 0, Qt::WFlags flags = 0);
	~QTime_Show2();

private:
	Ui::QTime_Show2Class ui;

	public slots:
		void onbtnStart();

public:
	int timerId;
	virtual void timerEvent(QTimerEvent* event);
};

#endif // QTIME_SHOW2_H

QTime_Show2.cpp

#include "qtime_show2.h"
#include <QTimer>
#include <QTime>
#include <QTimerEvent>

QTime_Show2::QTime_Show2(QWidget *parent, Qt::WFlags flags)
	: QMainWindow(parent, flags)
{
	ui.setupUi(this);
	connect(ui.btnStart,SIGNAL(clicked()),this,SLOT(onbtnStart()));
}

QTime_Show2::~QTime_Show2()
{

}

void QTime_Show2::onbtnStart()
{
	timerId=startTimer(1000);
}

void QTime_Show2::timerEvent(QTimerEvent* event)
{
	if(event->timerId()==timerId)
	{
		static int count=101;
		if(count!=0)
		{
			count--;
		}
		QString num=QString::number(count);
		ui.label->setText(num);
	}
}

main.cpp

#include "qtime_show2.h"
#include <QtGui/QApplication>

int main(int argc, char *argv[])
{
	QApplication a(argc, argv);
	QTime_Show2 w;
	w.move(700,400);
	w.resize(400,300);
	w.show();
	return a.exec();
}