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Re: WindowProc invoked while in Paint routine [message #40387 is a reply to message #40362]

Mon, 29 July 2013 19:38

mirek
Messages: 14260
Registered: November 2005

Ultimate Member

Well, this happens when you start message processing from Paint routine.

Typical example:

void MyApp::Paint(Draw& w)
{
    Progress pi;
    for(....) {
         pi.StepCanceled();
    }
}

The problem is that Win32 (not U++) does not handle this well, that is why it is checked.

While above example might seem obvious, I usually hit this error if Paint uses some sort of cached/lazy loaded data and loading of this data attempts to show the progress.

Mirek

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