本帖最后由 offffh 于 2015-11-23 16:50 编辑
楼主@yafeilinux ，谢谢你分享的教程。关于这个涂鸦板我有个问题想请教下你：
在加入pushButton去实现放大功能的之后，鼠标左键点击画点的时候，按理说只会画一些点，结果却经常会出现两点相连的情况。这个问题楼上几位也提到过。通过加入适当的qDebug()语句调试后，我发现问题出在有时候mousePressEvent事件触发之后，会莫名其妙导致多次重绘。解决办法我知道，可是为什么会出现这种情况？
这是加入的代码： pushButton = new QPushButton(this);
这是部分应用程序输出：（鼠标按下时，打印lastPoint；鼠标松开时，打印releasePoint；绘图时，打印绘制的线）
draw QPoint(0,0) to QPoint(0,0)
draw QPoint(0,0) to QPoint(0,0) draw QPoint(0,0) to QPoint(0,0) lastPoint QPoint(157,123) releasePoint: QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) lastPoint QPoint(168,137) draw QPoint(168,137) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) draw QPoint(157,123) to QPoint(157,123) releasePoint: QPoint(168,137) draw QPoint(157,123) to QPoint(168,137) draw QPoint(168,137) to QPoint(168,137) draw QPoint(168,137) to QPoint(168,137)
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