Qt--设计电子相册（上一张、下一张、开始播放、结束播放）

主要任务：

设计一个电子相册，点击上一张，切换到上一张图片，点击下一张，切换到下一张图片。

点击开始播放，图片循环播放，点击结束播放，图片停止播放。

设计方法：

使用QList存储各个图片的资源路径，QTimer定时器控制循环播放间隔时间。

 添加图片到项目目录中

 dialog.h

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>
//头文件
#include<QList>
#include<QTimer>

namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
    Q_OBJECT

public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();

private:
    Ui::Dialog *ui;
    QList<QString> list;
    int count=0;
    QTimer *timer;

private slots://槽函数
    void clickPeriousSlot();//点击上一张
    void clickNextSlot();//点击下一张
    void clickStartSlot();//开始播放
    void clickEndSlot();//结束播放
    void timeoutSlot();
};

#endif // DIALOG_H

 dialog.cpp

#include "dialog.h"
#include "ui_dialog.h"

Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);
    //创建定时器对象
    timer=new QTimer(this);
    //设置间隔时间
    timer->setInterval(1000);
    //设置周期性 true:单次性  false:周期性
    timer->setSingleShot(false);
    connect(timer,SIGNAL(timeout()),this,SLOT(timeoutSlot()));

    //设置图片
    QString img1(":/new/prefix1/flower.jpg");
    QString img2(":/new/prefix1/grass.jpeg");
    QString img3(":/new/prefix1/sand.jpeg");
    QString img4(":/new/prefix1/tree.jpg");
    QString img5(":/new/prefix1/water.jpg");

    //将图片以向后追加的方式存放到QList中
    list.push_back(img1);
    list.push_back(img2);
    list.push_back(img3);
    list.push_back(img4);
    list.push_back(img5);

    //连接槽函数
    connect(ui->pushButtonUp,SIGNAL(clicked()),this,SLOT(clickPeriousSlot()));
    connect(ui->pushButtonNext,SIGNAL(clicked()),this,SLOT(clickNextSlot()));
    connect(ui->pushButtonStart,SIGNAL(clicked()),this,SLOT(clickStartSlot()));
    connect(ui->pushButtonEnd,SIGNAL(clicked()),this,SLOT(clickEndSlot()));

}
//到时间会更新显示
void Dialog::timeoutSlot()
{
    count++;
    if(count==4)
        count=0;
    QSize size(ui->labelImg->width(),ui->labelImg->height());
    QPixmap img(list[count]);
    img = img.scaled(size,Qt::KeepAspectRatioByExpanding);
    ui->labelImg->setPixmap(img);
}

void Dialog::clickStartSlot()
{
    //启动定时器
    timer->start();
}
void Dialog::clickEndSlot()
{
   //关闭定时器
   timer->stop();
}
//上一张
void Dialog::clickPeriousSlot()
{
    if(count==0)
        count=4;
    else
        count--;
    QSize size(ui->labelImg->width(),ui->labelImg->height());
    QPixmap img(list[count]);
    img = img.scaled(size,Qt::KeepAspectRatioByExpanding);
    ui->labelImg->setPixmap(img);

}
//下一张
void Dialog::clickNextSlot()
{
    if(count==4)
        count=0;
    else
        count++;
    QSize size(ui->labelImg->width(),ui->labelImg->height());
    QPixmap img(list[count]);
    img = img.scaled(size,Qt::KeepAspectRatioByExpanding);
    ui->labelImg->setPixmap(img);
}
Dialog::~Dialog()
{
    delete timer;
    delete ui;
}