Toolwindow locking - Docking/MDI for Windows Forms Forum

Posted 19 years ago by Micah Alles

We have encountered a way to lock a simple application through interaction with docking ToolWindows. Our sample application has two ToolWindows, one with a checkbox added to it. If we drag the upper tool window onto the lower tool window and re-doc it in a way which should create a tabbed dock (the middle drop icon helper for the drop area) the application becomes unresponsive.

We are running .NET 1.1 on Windows XP and have seen this problem on the majority of our machines, including freshly installed and updated machines.

Here is a link to the simple project we used to expose the bug, it includes an instructions/ directory with screenshots showing how the bug can be instrumented and what the resulting hung application looks like:

Sample Application

Please let us know if there is any workaround to this issue, or if you require any additional information to help track this down or reproduce it.

Thank you,

--
Micah Alles micah@atomicobject.com
616-776-6020
Software Journeyman Atomic Object LLC

Comments (1)

Posted 19 years ago by Actipro Software Support - Cleveland, OH, USA

Hi Micah,

Thanks for the sample. I tried it here on the 1.0, 1.1, and 2.0 frameworks and couldn't duplicate the bug.

However this sounds like something we ran into a while back and thought we had worked around. The bug narrows down actually to a bug in the .NET framework that Microsoft made where Control.SelectNextControl can enter an infinite loop, thereby locking the application.

The strange thing was that it only happened on certain computers. We were never able to duplicate it and worked through our customers who could duplicate it, having them try code changes we made. Eventually we found a solution that stopped the problem for them and we haven't heard of any lockup issues since then.

If you want to email us, we can discuss further. Please let me know if you are running the latest UIStudio build in your email.

For further info on this Microsoft bug that we found in Google groups months back when we worked on it:
Posting 1
Posting 2

Actipro Software Support

The latest build of this product (v24.1.1) was released 3 days ago, which was after the last post in this thread.

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