QT实战之实现图片浏览系统

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QListWidget>
#include <QMainWindow>
#include <QTimer>
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
 
private slots:
    void on_btnOpen_clicked();
 
    void on_listWidget_itemClicked(QListWidgetItem *item);
 
    void MyFunction();
    void on_pushButton_clicked();
 
    void on_btnLast_clicked();
 
    void on_btnNext_clicked();
 
protected:
    bool eventFilter(QObject *watch, QEvent *evn);
 
    QStringList getFileNames(const QString &path);
private:
    Ui::MainWindow *ui;
 
    QVector<QString> mListPath;
    QTimer mTimer;
    int index ;
};
#endif // MAINWINDOW_H

#include "mainwindow.h"
#include "ui_mainwindow.h"
 
#include <QFileInfoList>
#include <QString>
#include <QDir>
#include <QMessageBox>
#include <QImage>
#include "qevent.h"
#include <QDebug>
#pragma execution_character_set("utf-8")
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    index =0;
    mTimer.setInterval(1000);
    connect(&mTimer,SIGNAL(timeout()),this,SLOT(MyFunction()));
    on_btnOpen_clicked();
    mTimer.start(1000);
    ui->btnOpen->setVisible(false);
   // ui->pushButton->setVisible(false);
    this->installEventFilter(this);
 
    this->setWindowTitle("图片浏览器");
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
 
void MainWindow::MyFunction()
{
    if (index == 5) {
        index = 0;
    } else {
        index++;
    }
    if (index == 5) {
        index = 0;
    }
 
    // this->setStyleSheet(QString("background-image: url(:/%1.png);").arg(index));
     QString strIndex = mListPath.at(index);
 
      qDebug()<<"index "<<QString::number(index)<<"strIndex "<<strIndex;
      QDir filePath(ui->inputDirPath->text());
 
    QString fullName = filePath.absoluteFilePath(strIndex);
    QImage img(fullName);
    QImage thumb = img.scaled(ui->label->width(),ui->label->height(),Qt::KeepAspectRatio);
    ui->label->setPixmap(QPixmap::fromImage(thumb));
}
void MainWindow::on_btnOpen_clicked()
{
 
   QString filePath = QCoreApplication::applicationDirPath()+"/pic";
   ui->inputDirPath->setText(filePath);
  // QMessageBox::infORMation(this,"提示！",filePath);
    QDir dir(filePath);
    // 判断文件夹是否存在
    if(dir.exists()){
        ui->listWidget->clear();
        QFileInfoList info_list = dir.entryInfoList(QDir::Files | QDir::Dirs | QDir::NoDotAndDotDot);
        for(int i =0;i<info_list.count();i++){
            ui->listWidget->addItem(info_list.at(i).fileName());
 
            mListPath.push_back(info_list.at(i).fileName());
        }
 
 
    }
    else{
        QMessageBox::information(this,"提示！","文件夹不存在");
    }
 
}
QStringList MainWindow::getFileNames(const QString &path)
{
    QDir dir(path);
    QStringList nameFilters;
    nameFilters << "*.jpg" << "*.png";
    QStringList files = dir.entryList(nameFilters, QDir::Files|QDir::Readable, QDir::Name);
    return files;
}
void MainWindow::on_listWidget_itemClicked(QListWidgetItem *item)
{
    if(mTimer.isActive())
      mTimer.stop();
    QDir filePath(ui->inputDirPath->text());
 
    QString fullName = filePath.absoluteFilePath(item->text());
    QImage img(fullName);
    QImage thumb = img.scaled(ui->label->width(),ui->label->height(),Qt::KeepAspectRatio);
    ui->label->setPixmap(QPixmap::fromImage(thumb));
 
 
}
//点击事件函数
bool MainWindow::eventFilter(QObject *watch, QEvent *evn)
{
    static int press_x;     //点击鼠标时获取的横坐标x
    static int press_y;     //点击鼠标时获取的纵坐标y
    static int relea_x;     //松开鼠标时获取的横坐标x
    static int relea_y;     //松开鼠标时获取的纵坐标y
 
    QMouseEvent *event = static_cast<QMouseEvent *>(evn);       //将图片QT QEvent 转换为 QMouseEvent ,QKeyEvent....等子类
    //获取点击鼠标（手指）时的坐标
    if (event->type() == QEvent::MouseButtonPress)
    {
            press_x = event->globalX();
            press_y = event->globalY();
    }
    //获取松开鼠标（手指）时的坐标
    if(event->type() == QEvent::MouseButtonRelease)
    {
        relea_x = event->globalX();
        relea_y = event->globalY();
 
 
    }
    //对鼠标（手指）滑动的方向进行判断(右滑)
    if((relea_x - press_x) > 5 && event->type() == QEvent::MouseButtonRelease && qAbs(relea_y - press_y) < 50)
    {
       on_btnNext_clicked();
    }
if( event->type() == QEvent::MouseButtonRelease)
     qDebug()<<"releax "<<QString::number(press_x - relea_x)<<"releay "<<QString::number(relea_y - press_y);
    //对鼠标（手指）滑动的方向进行判断(左滑)
    if((press_x - relea_x) > 5 && event->type() == QEvent::MouseButtonRelease && qAbs(relea_y - press_y) < 50)
    {
       on_btnLast_clicked();
    }
 
    return QWidget::eventFilter(watch, evn);
}
 
 
 
 
void MainWindow::on_pushButton_clicked()
{
    if(ui->pushButton->text()=="滑动切换")
    {
        ui->pushButton->setText("自动播放");
        if(mTimer.isActive())
          mTimer.stop();
    }
    else
    {
        ui->pushButton->setText("滑动切换");
        if(!mTimer.isActive())
          mTimer.start();
    }
}
 
void MainWindow::on_btnLast_clicked()
{
    if(index == -1)
    {
        index = 4;
    }
    else
    {
        index--;
    }
 
    if(index == -1)
    {
        index = 4;
    }
  //  this->setStyleSheet(QString("background-image: url(:/%1.png);").arg(index));
    QString strIndex = mListPath.at(index);
 
     qDebug()<<"index 111"<<QString::number(index)<<"strIndex "<<strIndex;
     QDir filePath(ui->inputDirPath->text());
 
     QString fullName = filePath.absoluteFilePath(strIndex);
    QImage img(fullName);
    QImage thumb = img.scaled(ui->label->width(),ui->label->height(),Qt::KeepAspectRatio);
    ui->label->setPixmap(QPixmap::fromImage(thumb));
}
 
void MainWindow::on_btnNext_clicked()
{
    if (index == 5) {
        index = 0;
    } else {
        index++;
    }
    if (index == 5) {
        index = 0;
    }
 
    // this->setStyleSheet(QString("background-image: url(:/%1.png);").arg(index));        //切换图片
     QString strIndex = mListPath.at(index);
 
      qDebug()<<"index "<<QString::number(index)<<"strIndex "<<strIndex;
      QDir filePath(ui->inputDirPath->text());
 
      QString fullName = filePath.absoluteFilePath(strIndex);
    QImage img(fullName);
    QImage thumb = img.scaled(ui->label->width(),ui->label->height(),Qt::KeepAspectRatio);
    ui->label->setPixmap(QPixmap::fromImage(thumb));
}