Zugg Software :: View topic - RightClick->close on task bar doesn't close right.

Posted: Wed Nov 24, 2004 4:49 am

If you right-click on a zApp instance in the windows taskbar and pick 'Close', it gives you a COM Server Warning saying that if you close this manually, it may cause other clients with references to the COM objects to fail.

Posted: Wed Nov 24, 2004 5:09 am

Grrr...I really hate windows sometimes. How many ways do they need to close an application anyway? They have the File/Exit command, they have the X box in the corner of the window caption, and now they have Close in the Taskbar. The problem is that each of these methods DOES SOMETHING DIFFERENT! Windows doesn't seem to have any consistent way to close down applications. What your bug report means is that Windows is not sending the WM_CLOSE message to the application window properly and it trying to force a shutdown. This bypasses all of the normal routines that check to see if you want to save your data and which properly clean up COM objects.

I'd really try to avoid using that method to close applications since you could easily loose data, or not get your settings saved. But I'll look into it and see if I can find a way to trap that particular method of closing and clean up the COM objects. Sigh. I really hate Windows some days.

Wizard Joined: 10 Oct 2000 Posts: 1551 Location: Australia

I always thought that all those different close methods called PostQuitMessage( ) but obviously not... stupid windows heh.

I bet that the 'X' box sends two different messages too, one for normal 'X' and one for 'end task X'.

I think I've seen a similar COM server warning when exiting Zmud but I don't recall what sequence it was I used, I'll try and remember to post next time I see it heh.

Posted: Wed Nov 24, 2004 10:17 pm

OK, I was able to fix this. Sure enough, selecting Close from the right-click menu on the task bar forces an immediate application termination. None of the "CanClose" routines are called. So, applications that normally display a box saying "Your file has changed...save before closing?" and stuff like that are not called. This means that in many applications, using the right-click close method from the task bar will likely not save any changes you have made to files, so you can loose data doing this. Definitely not a good habit to have.

But in any case, in zApp I now trap the Terminate thread and check to see if all of the COM objects used in zApp have been cleaned up, and if not, I go ahead and do it then. This fixes the COM warning message that you were getting.

New release soon!