ATL ActiveX Control Hang RRS feed

  • Question

  • Hi,

    We have control(ActiveX) which used to integrate with a 3rd party Application and in few situation its hanging/freezing up.

    Following is the window structure

    The Parent Control and subsequent children :  ATL ActiveX -> .Net Usercontrol -> Tab Controls -> Treeviews/Textboxes etc.

    We earlier also faced issue  of  our control freezing/hanging while doing tab on text boxes and fixed that up  using the WS_EX_CONTROLPARENT . Now this flag was set for both the ActiveX and the .Net UserControl.

    Now at a certain client app  this  control hangs on doing ALT-TAB to switch windows and when we get back to our control its frozen with high CPU. Now the finding is if we remove the WS_EX_CONTROLPARENT from both the ActiveX and the .NET Control it doesn't occur.  Little confusing for us and we read up MSDN and  other blogs although not clear how to approach this problem.

    Any pointers ?

    Thanks and Regards 

    Monday, December 19, 2016 9:36 AM

All replies

  • what is the call stack when it hangs? what is the last windows message of the UI thread reported by spy++? Do you get WM_ACTIVATE or WM_ACTIVATEAPP?

    Visual C++ MVP

    Monday, December 19, 2016 3:29 PM
  • Hi,

    the Issue is resolved after we recursively  had set WS_EX_CONTROLPARENT  to all the .net Controls which are in the hierarchy.


    Wednesday, March 15, 2017 7:12 AM