In GUI applications, the main thread is also called the GUI thread because it's the only thread that is allowed to perform GUI-related operations.
And the class QThread is non-Gui thread,so you cann`t use the GUI class Qpixmap in it.
这个是qt定的,所以没有办法解决
ps,虽然不能使用Qpixmap ,但可以使用QImage,如有需要可以在线程外面将QImage转换成QPixmap