截取屏幕

#ifndef MAINWINDOW_H

#define MAINWINDOW_H

#include <QMainWindow>

#include <QTimer>  //定时期

#include <QPixmap>  //图像类

#include <QDesktopWidget>  //desktopwidget类提供对多头系统上屏幕信息的访问。

#include <QMessageBox>

namespace Ui {

class MainWindow;

}

class MainWindow : public QMainWindow

{

    Q_OBJECT

public:

    explicit MainWindow(QWidget *parent = 0);

    ~MainWindow();

private slots:

    void on_newSreenShotbutton_clicked();

    void shotScreenSlot();

    void on_savePicturebutton_clicked();

private:

    Ui::MainWindow *ui;

    QTimer *timer;

    QPixmap pixmap;

};

#endif // MAINWINDOW_H

#include "mainwindow.h"

#include "ui_mainwindow.h"

#include <QScreen>  //The QScreen class is used to query screen properties qscreen类用于查询屏幕属性

#include <QFileDialog>  //获取文件路径

#include <QDesktopServices>  //桌面服务

#include <QClipboard>   //剪切版

#include <QDebug>

//storagelocation

//把内容放到剪切版剪切版   进程通信

MainWindow::MainWindow(QWidget *parent) :

    QMainWindow(parent),

    ui(new Ui::MainWindow)

{

    ui->setupUi(this);

}

MainWindow::~MainWindow()

{

    delete ui;

}

void MainWindow::on_newSreenShotbutton_clicked()

{

   if(ui->checkBox->isChecked())  //  单选框

        {

        this->hide();

        this->timer = new QTimer;
//连接  定时期信号 和截屏槽函数

        QObject::connect(timer,SIGNAL(timeout()),this,SLOT(shotScreenSlot()));

        //启动定时器

        this->timer->start(ui->spinBox->value()*1000);

    }

    else

        {

        qApp->beep();

    }

    /*

    QClipboard *clipboard = QGuiApplication::clipboard();

     QString originalText = clipboard->text();

     ...

     clipboard->setText(newText);

    */

}

void MainWindow::shotScreenSlot()

{

    //pixmap  当前应用程序所在屏幕 抓取

   // QScreen::grabWindow();

   // QScreen screen(this);

    this->pixmap = QPixmap::grabWindow(QApplication::desktop()->winId());

// 图片的大小     为label_3 的大小

    ui->label_3->setPixmap(this->pixmap.scaled(ui->label_3->size()));

    //打开系统剪切版

    QClipboard *clipboard = QGuiApplication::clipboard();

     //QString originalText = clipboard->text();  //获得剪切版内的文本

    // ...  把图片放到剪切版

     clipboard->setPixmap(this->pixmap);

   qDebug()<<clipboard->pixmap().size();

    this->show();

    this->timer->stop();

}

void MainWindow::on_savePicturebutton_clicked()

{//QDesktopServices::storageLocation(QDesktopServices::DataLocation)

 // QString filename=QFileDialog::getSaveFileName(this,"savefile",QDesktopServices::storageLocation(QDesktopServices::PicturesLocation);/home/centos/grapSreen/mainwindow.cpp:63: error: ‘storageLocation’ is not a member of ‘QDesktopServices’

          QString filename=QFileDialog::getSaveFileName(this,"savefile","/home/centos/图片");

  //pixmax 提供了保存接口

  this->pixmap.save(filename);

}