QT入门例程【3】

在练习qt中时间类的使用，下边派生类，该类会显示变色的圆圈，可以通过传入参数设计定圆圈的颜色，同时，类对象有生存期，时间超时后，对象消亡。

 

#ifndef MOVIE_H
#define MOVIE_H
#include <QWidget>
#include <QTimer>
#include <QPaintEvent>
#include <QTimer>
#include <QPainter>
class movie:public QWidget
{
    Q_OBJECT
    public:
        movie(QWidget *parent=0);
        static int movie_num;
    private:
        int movie_times;
        int wait_sec;
        int tmp;
        QPainter *painter;
        QTimer *wait_timer,*flash_timer;
    protected:    
        void paintEvent(QPaintEvent *event);
    public slots:
        void stop(void);
        void start(void);
    signals:
        void timeout(void);        
};

#endif


#include "movie.h"
#include <QWidget>
#include <QTimer>
#include <QPainter>
int movie_num=0;
movie::movie(QWidget *parent):QWidget(parent)
{
    tmp=0;
    wait_sec=10;
    movie_times=500;
    wait_timer=new QTimer(this);
    flash_timer=new QTimer(this);
    wait_timer->start(wait_sec*1000);
    flash_timer->start(movie_times);
    connect(flash_timer,SIGNAL(timeout()),this,SLOT(update()));
    connect(wait_timer,SIGNAL(timeout()),this,SLOT(close()));
}    

void movie::stop(void)
{
    flash_timer->stop();
    wait_timer->stop();
    emit this->timeout();
}    

void movie::start(void)
{
    flash_timer->start();
    wait_timer->start();    
}    

void movie::paintEvent(QPaintEvent *)
{
    
    painter=new QPainter(this);
    if((tmp++)==0)
    {
        painter->setPen(Qt::NoPen);
        painter->setBrush(Qt::blue);
        painter->drawEllipse(10,10,40,40);
    }    
    else
    {
        tmp=0;
        painter->setPen(Qt::NoPen);
        painter->setBrush(Qt::red);
        painter->drawEllipse(10,10,40,40);
        
    }
    delete painter;
}