10.QT-定时器

int QObject::startTimer(int interval);
//启动定时器,并设置定时器间隔时间(单位ms),启动后返回该定时器ID号.

void QObject::timerEvent(QTimerEvent * event);
//定时器处理函数,需要用户来重写它,如果有多个定时器,可以通过QTimerEvent::timerId()来判断定时器ID处理

void killTimer(int id);
//通过定时器ID号来杀掉某个定时器

#ifndef WIDGET_H
#define WIDGET_H
#include <QWidget>
#include <QObject>

class Widget : public QWidget
{
    Q_OBJECT

private:
virtual void  timerEvent( QTimerEvent * event );

public:
    explicit Widget(QWidget *parent = 0);
};

#endif // WIDGET_H

#include "Widget.h"
#include <QDebug>
#include <QTimerEvent>

Widget::Widget(QWidget *parent) :
    QWidget(parent)
{
     int TimerID = startTimer(1000);        //设置1000ms为单位
     qDebug()<<"startTimerID : "<<TimerID;
}

void Widget::timerEvent(QTimerEvent * event )
{
    qDebug()<<"TimerID : "<<event->timerId();
}

QTimer *timer = new QTimer(this);

 connect(timer, SIGNAL(timeout()), this, SLOT(time_handler()));

timer->start (int msec);               //单位ms

timer->stop();

delete timer;

void   setSingleShot(bool singleShot);
// 设置使能单次触发和多次触发,默认情况为多次触发

bool   isActive();
//判断定时器是否运行

bool  setInterval ( int msec );
//从新设置间隔时间

#ifndef WIDGET_H
#define WIDGET_H
#include <QWidget>
#include <QObject>

class Widget : public QWidget
{
    Q_OBJECT

    QTimer *timer;

private slots:
     void  time_handler();

public:
    explicit Widget(QWidget *parent = 0);
};

#endif // WIDGET_H

#include "Widget.h"
#include <QDebug>
#include <QTimer>

Widget::Widget(QWidget *parent) :
    QWidget(parent)
{
     QTimer *timer = new QTimer(this);
     connect(timer, SIGNAL(timeout()), this, SLOT(time_handler()));
     timer->start(1000);        //1000ms
}

void Widget::time_handler()
{
    qDebug()<<"Timer out";

}