Uncaught Exception in TreeListBox.ClearSelection()

Hi John,

Nothing should normally be causing that on our end unless you perhaps are doing some other modification to the tree in another thread.  Are you perhaps modifying the tree in another thread?

Are you able to make a new simple sample project that shows this happening that you could email to our support address?  Then we could debug with that to see what's going on.  If you can, please make sure you remove the bin/obj folders from what you send and rename the .zip file extension so it doesn't get spam blocked.  Thanks!

No, there aren't any other threads involved. I can send you my existing application but narrowing it down to a simple case will take a little time.

Hi John,

We'd really need a new very simple app that just shows this problem.  Our next build is planned for a week or so out, so as long as you could get us something before that (in case code updates are needed), that would be ideal.  Thanks!

I don't have a simple repro case yet but I do think I know what might be causing the issue. My tree of items can have replicated data in it

A
+ B
  + C
  + D
+ E
F
+ G
+ B
  + C 
  + D  

 The B is node is not a copy - it's the same object that occurs twice in the tree. This seems to cause the issue with just selecting things. I disabled drag and drop and by just selecting various items I can cause the issue.

Hi John,

Yes we do track our data behind the scenes with some Equals() checks.  So if you have an item that returns Equals() with another item in the tree, then that could certainly cause problems.  Perhaps you could wrap them in some other object when databinding in our tree to keep them from being equal?

That would be quite a change to my application - is something that you never plan on supporting?

Hi John,

Behind the scenes, we are making a flat list of all the items and that becomes the true items source of the control.  Doing this allows us to obtain very fast speed for the control.  That being said, since the control is designed specifically for heavy MVVM usage, there are cases where we are passed a simple data object and need to find a matching TreeNode (internal class) that wraps it in our flat list.  That process is where the equals comes into play.  If you have more than one data item that are equal, then we might end up grabbing the wrong TreeNode wrapper.  I'm not sure there's really anything we can change our internal design to help with that scenario.  I'm sorry but the only workaround is probably to ensure that the data items bound to the tree don't have equality.

That being said, if you can send a new simple sample project that reproduces the problems to our support address and reference this thread, we can debug with it to see if there is anything we can do.  Please remove any bin/obj folders from the ZIP you send and rename the .zip file extension so it doesn't get spam blocked.  Thanks!

I've reproduced using a simple example and created support ticket 33C-21C471B1-0018