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本文章博客地址：https://blog.csdn.net/qq21497936/article/details/79177272
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红胖子(红模仿)的博文大全：开发技术集合（包含Qt实用技术、树莓派、三维、OpenCV、OpenGL、ffmpeg、OSG、单片机、软硬结合等等）持续更新中…（点击传送门）
Qt开发专栏：实用技巧（点击传送门）
需求
写一个截屏模块。
Demo
下载地址： http://download.csdn.net/download/qq21497936/10226423
效果截图
核心代码
初始化截屏窗口代码
// 设置无边框 setWindowFlags(windowFlags() | Qt::FramelessWindowHint); // 激活并全屏 setWindowState(Qt::WindowActive | Qt::WindowFullScreen); // 抓取当前屏幕图片，使用QPixmap，Qt5.9.3会有提示信息 // this function is deprecated, use QScreen::grabWindow() instead. // Defaulting to primary screen. _pixmapScreen = QPixmap::grabWindow(QApplication::desktop()->winId()); _screenWidth = _pixmapScreen.width(); _screenHeight = _pixmapScreen.height();
绘制代码
QPainter painter(this); // 背景刷图 QColor shadowColor = QColor(0, 0, 0, 100); painter.drawPixmap(0, 0, _pixmapScreen); painter.fillRect(_pixmapScreen.rect(), shadowColor); if(_bPressed) { QRect selectedRect(_pointStart, _pointEnd); // QRect允许负值，使用mormalized转化为正值 selectedRect = selectedRect.normalized(); // 截图黑框 painter.setPen(QPen(Qt::black, 2)); painter.drawRect(selectedRect); // 截图的rect，再次填充 _pixmapCaptrueScreen = _pixmapScreen.copy(selectedRect); painter.drawPixmap(selectedRect.topLeft(), _pixmapCaptrueScreen); }
鼠标操作代码
void CaptureScreen::mousePressEvent(QMouseEvent *event) { if(event->button() == Qt::LeftButton) { _bPressed = true; _pointStart = event->pos(); _pointEnd = event->pos(); update(); } } void CaptureScreen::mouseMoveEvent(QMouseEvent *event) { _pointEnd = event->pos(); update(); } void CaptureScreen::mouseReleaseEvent(QMouseEvent *event) { if(event->button() == Qt::LeftButton) { _bPressed = false; _pointEnd = event->pos(); update(); emit capturePixmapFnished(true, _pixmapCaptrueScreen); close(); }else{ emit capturePixmapFnished(true, _pixmapCaptrueScreen); close(); } }
原博主博客地址： https://blog.csdn.net/qq21497936
原博主博客导航： https://blog.csdn.net/qq21497936/article/details/102478062
本文章博客地址： https://blog.csdn.net/qq21497936/article/details/79177272
