qt截图

QT截图

---

#ifndef CAPTURESCREEN_H
#define CAPTURESCREEN_H


#include <QWidget>
#include <QPainter>
#include<QRect>
#include<QLabel>
#include<QClipboard>
class CaptureScreen : public QWidget
{
   
   
    Q_OBJECT

public:
    CaptureScreen(QWidget *parent = 0);
    ~CaptureScreen();
    QRect getRect(const QPoint &beginPoint, const QPoint &endPoint);

Q_SIGNALS:
    void signalCompleteCature(QPixmap catureImage);

private:
    void initWindow();                          //初始化窗口
    void loadBackgroundPixmap();                //获取整个窗口下来

    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent* event);
    void mouseReleaseEvent(QMouseEvent *event);
    void keyPressEvent(QKeyEvent *event);
    void paintEvent(QPaintEvent *event);
    QRect changePosition(const QPoint &beginPoint, const QPoint &endPoint);

private:
    bool m_isMousePress1=false,m_isMousePress2=false; //鼠标是否被按下
    QPixmap m_loadPixmap, m_capturePixmap;      //pixmap加载和捕获
    int m_screenwidth;                          //屏幕的宽度
    int m_screenheight;                         //屏幕的高度
    QPoint m_beginPoint, m_endPoint;            //开始点和结束点的坐标
    QPainter m_painter;                         //画笔
    QPoint m_changePoint,m_begin_movePonit,m_end_movePoint;//移动，改变大小
    QClipboard *clip;
    QRect selectedRect;
    int flag=0;
    // 四个角坐标;
    QPoint topLeft;
    QPoint topRight ;
    QPoint bottomLeft ;
    QPoint bottomRight;
    // 四条边中间点坐标;
    QPoint leftCenter ;
    QPoint topCenter ;
    QPoint rightCenter ;
    QPoint bottomCenter ;

};
#endif // CAPTURESCREEN_H

#include "capturescreen.h"
#include <QApplication>
#include <QDesktopWidget>
#include <QMouseEvent>
#include<QDebug>
/*
 * 截图：把选定的图的放在剪贴板
 * 原理：
 * 1.利用QPixMap::grabWindow抓取图片m_loadPixmap
 * 2.重绘事件，让m_loadPixmap布上阴影
 * 3.对窗口进行选取，然后得到m_capturePixmap
 * 4.复制进剪贴板
 *
*/
CaptureScreen::CaptureScreen(QWidget *parent)
    : QWidget(parent)
    , m_isMousePress1(false)
{
   
   
    initWindow();
    loadBackgroundPixmap();
}

CaptureScreen::~CaptureScreen()
{
   
   

}

void CaptureScreen::initWindow()
{
   
   
    this->setMouseTracking(true);
    this->setWindowFlags(Qt::FramelessWindowHint);//无法进行移动和调整大小
    setWindowState(Qt::WindowActive | Qt::WindowFullScreen);//激活窗口，全屏
}

void CaptureScreen::loadBackgroundPixmap()
{
   
   
    m_loadPixmap = QPixmap::grabWindow(QApplication::desktop()->winId()); //抓取当前屏幕的图片;
    m_screenwidth = m_loadPixmap.width();
    m_screenheight = m_loadPixmap.height();
}

void CaptureScreen::mousePressEvent(QMouseEvent *event)//鼠标被按下，记录起点
{
   
   
    if (event->button() == Qt::LeftButton)
    {
   
   
        m_isMousePress1 = true;
        m_isMousePress2 = true;
        if(flag==1)
        {
   
   
            m_isMousePress1=false;
            m_begin_movePonit=event->pos();
        }
        else if(flag==0)
        {
   
   

            m_beginPoint = event->pos();
        }
    }

    return QWidget::mousePressEvent(event);
}

void CaptureScreen::mouseMoveEvent(QMouseEvent* event)//鼠标移动
{
   
   
    if (m_isMousePress1)
    {
   
   
        m_endPoint = event->pos();
        update();
        flag=1<