今天我,
在QT中用QPainter在mouseMoveEvent中画图时出现如下错误：
QPainter::begin: Widget painting can only begin as a result of a paintEvent
QPainter::begin: Painter already active
解决方法:
在QT4.1中QPainter只能在paintEvent中画图在其他地方就会产生如上的错误.
或者设置部件的属性允许在paintEvent事件外绘画:
setAttribute(Qt::WA_PaintOutsidePaintEvent).