Callingwidth(),height(),size()orrect()insidesubclassofQWidgetendswithsegfault我对QWidget的width()、height()、size()或rect()功能有疑问；当它被调用时，它会出现段错误。它是Qt4.7。这是有问题的类的标题：classPlotCanvas:publicQWidget{  voidpaintEvent(QPaintEvent*e);  uint64_tsmallestDiv();  uint64_tlongestLength();  voiddrawGrid(QPainter*painter

Callingwidth(),height(),size()orrect()insidesubclassofQWidgetendswithsegfault我对QWidget的width()、height()、size()或rect()功能有疑问；当它被调用时，它会出现段错误。它是Qt4.7。这是有问题的类的标题：classPlotCanvas:publicQWidget{  voidpaintEvent(QPaintEvent*e);  uint64_tsmallestDiv();  uint64_tlongestLength();  voiddrawGrid(QPainter*painter