我发现了我的问题-我忘记了删除画家，这在事后看来很明显（不是总是这样吗？）。最后添加“ del painter”可使代码正常工作。这是工作代码：
def printer(self): "Prints the current diagram" # Create the printer printerobject = QtGui.QPrinter(0) # Set the settings printdialog = QtGui.QPrintDialog(printerobject) if printdialog.exec_() == QtGui.QDialog.Accepted: # Print pixmapImage = QtGui.QPixmap.grabWidget(self.contentswidget) painter = QtGui.QPainter(printerobject) painter.drawPixmap(0, 0, pixmapImage) del painter
