[PyQt] QPainter::end: Painter ended with 2 saved states
hpj at urpla.net
Tue Jun 28 20:05:20 BST 2011
On Tuesday 28 June 2011, 20:52:12 Eric Frederich wrote:
> I was trying to get an example working with a QThread.
> I wound up creating one but after running it for a while and pressing
> buttons I got the error...
> QPainter::end: Painter ended with 2 saved states
> Am I doing something wrong?
> I wanted an example where a worker thread would query a database or
> some other long running operation and leave the GUI responsive
> (although disabling certain elements like the button it was launched
> This is the code I was running....
> from PyQt4.QtCore import *
> from PyQt4.QtGui import *
> class Blah(QThread):
> def __init__(self, parent=None):
> super(Blah, self).__init__(parent)
> print 'new thread created'
> def run(self):
> print 'running'
> import time
> for i in xrange(10):
> self.parent().setText("%02d" % i)
> self.parent().setText("Push Me")
You're doing "bad" things here, that you shouldn't do from a thread,
e.g. using methods, that trigger redraws. You should create signals in
your thread, that signals operations to the main thread, where you
would actually process these operations without fear.
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