QT：制作图片浏览器

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include 

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

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

private slots:

    void on_pb_2_clicked();

    void on_pb_left_clicked();

    void on_pb_3_clicked();

private:
    Ui::Widget *ui;
    static int i;   //索引
    QStringList picfiles;   //存储路径
};

#endif // WIDGET_H

widget.cpp

#include "widget.h"
#include "ui_widget.h"
#include   //文件对话框

int Widget::i = 0;  //初始化i为0

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    setWindowTitle("图片浏览器");
    setFixedSize(530,500);

    ui->setupUi(this);   //ui操作在此下面写
}

Widget::~Widget()
{
    delete ui;
}

void Widget::on_pb_2_clicked()
{
    picfiles = QFileDialog::getOpenFileNames(this,"打开图片","..","图片文件(*.png)");  //父类、窗口标题、上一级路径打开、文件类型
    ui->te->setText(picfiles[i]);
    ui->lb_2->setScaledContents(true);   //设置标签自适应大小
    ui->lb_2->setPixmap(QPixmap(picfiles.at(i)));  //设置标签中装入索引为i的图片
}

void Widget::on_pb_left_clicked()
{
    if(i != 0)
    {
       ui->te->setText(picfiles[--i]);
       ui->lb_2->setPixmap(QPixmap(picfiles.at(i)));
    }
    else
    {
        ui->te->setText(picfiles[picfiles.size()-1]);
        ui->lb_2->setPixmap(QPixmap(picfiles.at(picfiles.size()-1)));
        i = picfiles.size()-1;
    }
}

void Widget::on_pb_3_clicked()
{
    if(i != picfiles.size()-1)
    {
       ui->te->setText(picfiles[++i]);
       ui->lb_2->setPixmap(QPixmap(picfiles.at(i)));
    }
    else
    {
        ui->te->setText(picfiles[0]);
        ui->lb_2->setPixmap(QPixmap(picfiles.at(0)));
        i = 0;
    }
}

main.cpp

#include "widget.h"
#include 

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget w;
    w.show();

    return a.exec();
}

widget.ui

结果