Ubuntu上Qt之简单图片浏览器

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>>主要功能：

（1）图片切换浏览， 上一张/下一张 。

（2）图片 放大、缩小 。包括两种机制：鼠标滚轮和按钮放大/缩小。

（3）图片 自动循环播放 ，间隔2s。点击播放后，其他操作均无效，直至点击暂停。

（4）图片顺时钟旋转，每次90度。可在放大/缩小状态下旋转，或者相反。

（5）在图片被放大/缩小/旋转后，点击还原或者切换图片时，自动恢复为默认大小。

>>最终效果：

（1）点击播放按钮：

（2）暂停后，点击下一张：

（3）点击放大（或鼠标滚轮往前滚动）：

（4）点击还原：

（5）点击缩小（或鼠标滚轮往后滑动）：

（6）点击上一张：

（7）点击旋转：

（8）点击缩小（或鼠标滚轮往后）：

（9）点击还原：

>>添加程序：

新建Gui工程，名为MyPictureView，类名MyPictureView，基类选择QWidget。

mypictureview.h

#ifndef MYPICTUREVIEW_H

#define MYPICTUREVIEW_H

#include <QWidget>

#include <QVector>

#include <QPixmap>

#include <QTimer>

#include <QFileDialog>

#include <QString>

#include <QLabel>

#include <QWheelEvent>

namespace Ui {

class MyPictureView;

}

class MyPictureView : public QWidget

{

    Q_OBJECT

public:

    MyPictureView(QVector<QPixmap *> &pictures);

    ~MyPictureView();

private slots:

    void on_btn_prev_clicked();

    void on_btn_spin_clicked();

    void on_btn_play_stop_clicked();

    void on_btn_orig_clicked();

    void on_btn_next_clicked();

    void on_btn_big_clicked();

    void on_btn_smal_clicked();

    void wheelEvent(QWheelEvent * event);

    void pic_showloop();

private:

    Ui::MyPictureView *ui;

    QVector<QPixmap *>  &pictures_;

    QTimer *timer;

    QPixmap pix;

    QLabel *label;

    void pic_show1();

    void pic_show2();

    bool isPlaying;

    float scale;

    int size;

    int currentIndex;

    int imageAngle;

};

#endif // MYPICTUREVIEW_H

mypictureview.h

mypictureview.cpp

#include "mypictureview.h"

#include "ui_mypictureview.h"

MyPictureView::MyPictureView(QVector<QPixmap *> &pictures)

    : pictures_(pictures),

    ui(new Ui::MyPictureView)

{

    ui->setupUi(this);

    scale = ;

    currentIndex = ;     // Current picture index

    size = pictures_.size();

    isPlaying = false;

    imageAngle = ;

    label = new QLabel;

    ui->scrollArea->setWidget(label);

    ui->scrollArea->setAlignment(Qt::AlignCenter);   //显示位置，对齐方式

    timer = new QTimer;

    timer->setInterval( * );   //2s

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

    label->setAlignment(Qt::AlignCenter);

    if(size > )

        pic_show1();

}

MyPictureView::~MyPictureView()

{

    delete ui;

}

void MyPictureView::on_btn_prev_clicked()       //上一张

{

    timer->stop();

    scale = ;

    imageAngle = ;

    currentIndex--;

    if(currentIndex<)

        currentIndex=size-;

    pic_show1();

}

void MyPictureView::on_btn_spin_clicked()       //旋转

{

    imageAngle += ;

    imageAngle = imageAngle % ;

    pic_show2();

}

void MyPictureView::on_btn_play_stop_clicked()      //播放、暂停，间隔2s

{

    isPlaying = !isPlaying;

    if(isPlaying)

    {

        ui->btn_play_stop->setText(tr("暂停"));

        timer->start();

        ui->btn_big->setEnabled(false);

        ui->btn_next->setEnabled(false);

        ui->btn_orig->setEnabled(false);

        ui->btn_prev->setEnabled(false);

        ui->btn_smal->setEnabled(false);

        ui->btn_spin->setEnabled(false);

    }

    else

    {

        ui->btn_play_stop->setText(tr("播放"));

        timer->stop();

        ui->btn_big->setEnabled(true);

        ui->btn_next->setEnabled(true);

        ui->btn_orig->setEnabled(true);

        ui->btn_prev->setEnabled(true);

        ui->btn_smal->setEnabled(true);

        ui->btn_spin->setEnabled(true);

    }

}

void MyPictureView::on_btn_orig_clicked()       //还原

{

    timer->stop();

    scale = ;

    imageAngle = ;

    pic_show1();

}

void MyPictureView::on_btn_next_clicked()       //下一张

{

    timer->stop();

    scale = ;

    imageAngle = ;

    currentIndex++;

    if(currentIndex>size-)

        currentIndex = ;

    pic_show1();

}

void MyPictureView::on_btn_big_clicked()        //放大

{

    timer->stop();

    scale = scale*1.25;         //和0.8对应，放大次数和缩小次数点击相同次，会还原到原来的样子

    if(imageAngle != )

        pic_show2();

    else

        pic_show1();

}

void MyPictureView::on_btn_smal_clicked()       //缩小

{

    timer->stop();

    scale = scale*0.8;

    if(imageAngle != )

        pic_show2();

    else

        pic_show1();

}

void MyPictureView::wheelEvent(QWheelEvent *event)          //滚轮放大或缩小

{

    int num = event->delta();

    if(!isPlaying)

    {

        if(num > )

            on_btn_big_clicked();

        else

            on_btn_smal_clicked();

    }

}

void MyPictureView::pic_show1()          //显示图片

{

    pix = (*pictures_[currentIndex]).scaled(*scale,*scale,Qt::KeepAspectRatio);

    label->setPixmap(pix);

}

void MyPictureView::pic_show2()     //旋转后的显示

{

    QMatrix leftmatrix;

    leftmatrix.rotate(*imageAngle);

    pix = (*pictures_[currentIndex]).scaled(*scale,*scale,Qt::KeepAspectRatio);

    label->setPixmap(pix.transformed(leftmatrix,Qt::SmoothTransformation));

}

void MyPictureView::pic_showloop()      //循环显示图片

{

    scale = ;

    currentIndex ++;

    if(currentIndex > size-)

        currentIndex = ;

    pic_show1();

}

mypictureview.cpp

main.cpp

#include "mypictureview.h"

#include <QApplication>

int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    QVector<QPixmap *> pictures;

    pictures.push_back(new QPixmap(":/pictures/1"));

    pictures.push_back(new QPixmap(":/pictures/2"));

    pictures.push_back(new QPixmap(":/pictures/3"));

    pictures.push_back(new QPixmap(":/pictures/4"));

    pictures.push_back(new QPixmap(":/pictures/5"));

    pictures.push_back(new QPixmap(":/pictures/6"));

    pictures.push_back(new QPixmap(":/pictures/7"));

    pictures.push_back(new QPixmap(":/pictures/8"));

    MyPictureView view(pictures);

    // Disable maximize and minimize button

    view.setWindowFlags(view.windowFlags()

                    & ~Qt::WindowMaximizeButtonHint

                    & ~Qt::WindowMinimizeButtonHint);

    view.show();

    return a.exec();

}