Qt ------ 截图、获取鼠标指定的RGB值

获取RGB值思路：截图，获取图片的（0，0）的RGB值

    int x = QCursor::pos().x();
    int y = QCursor::pos().y();
  // QPixmap pixmap = QPixmap::grabWindow(QApplication::desktop()->winId(), x, y, 1, 1);

    QList<QScreen *> list_screen =  QGuiApplication::screens(); //可能电脑接了多个屏幕

    QPixmap pixmap = list_screen.at(0)->grabWindow(0,x,y,1,1);
    if (!pixmap.isNull()) //如果像素图不为NULL
    {
        QImage image = pixmap.toImage();//将像素图转换为QImage
        if (!image.isNull()) //如果image不为空
        {
            if (image.valid(0, 0)) //坐标位置有效
            {
                QColor color = image.pixel(0, 0);
                mousedPressed_R = color.red();
                mousedPressed_G = color.green();
                mousedPressed_B = color.blue();
                QString text = QString("RGB: %1, %2, %3").arg(mousedPressed_R).arg(mousedPressed_G).arg(mousedPressed_B);
                qDebug() << text;
            }
        }
    }