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Thread: Qt GUI Dialog update widgets Labels - freeze

  1. #1
    Join Date
    Feb 2016
    Qt products
    Qt4 Qt5
    Unix/X11 Windows

    Default Qt GUI Dialog update widgets Labels - freeze


    I have developed an Qt [4.8.4- Windows XP] application to receive data from CAN communication and Serial Port using Q Threads.

    My Main Window [Q Dialog] have all the widgets for the GUI update.

    On execution the application work for almost 20 minutes and after that the GUI update stops. I am using a Touch Screen based display.

    When i touch the screen / move mouse / Keypad events wakes up the GUI and the update is working.

    I have used repaint() and Update() for all the widgets and dialog and its not working. What could be the problem?

    Is there any way i can call refresh screen from Qt or simulate events to make my screen active. Please guide

  2. #2
    Join Date
    Jan 2006
    Graz, Austria
    Thanked 1,546 Times in 1,496 Posts
    Qt products
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    Unix/X11 Windows

    Default Re: Qt GUI Dialog update widgets Labels - freeze

    You could investigate if you ever call update() or repaint() accidentally from a thread.
    Also check if any updating/painting method interacts with locks and whether those locks are held longer than you expect.

    You could also start a timer in the main thread and have it regularily log a time stamp to a file and then check if it has longer interval between logs than expected.


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