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Qt Gui freezes on startup half of the time after upgrading to 5.2

  • Hi all,
    I implemented a kind of complex GUI in Qt unsing also vtk features (That means I use QVTKWidget). That worked quite good, until I upgraded Qt to version 5.2.1. When I start the program, to cases are possible with the same probability: a) everything works as expected. b) the gui starts (with correct size), but is filled white (or light gray). Then I am not able to move or resize the gui and have to close it in the hard way. I use Visual Studio 2010 and the error occurs in both release and debug mode. Unfortunatly, if I set a break point before the application.exec() and stop there, the program starts successfully after going further.

    So, it is hard to write a minimal example in this case. But is there any idea where I could start to search for the problem and how? Which information can I add?

    Sry for being so confused.

    kind regards,

  • Qt Champions 2017

    You must be doing some time consuming activity in main. Since this involves your complex UI, you need start analysing the functionality which is taking time. Start disabling many of the functionality and see how it goes. One main thing is that main UI thread is doing some time consuming task. You should identify and move the time consuming task to worker thread.

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