wpf comboboxes causeing null reference crash when visibility or width used in code

I filled a combobox in codebehind and it works correctly. I also set its visibilty to visibility.collapsed in the same function without problem.

when I try to set it to visibility.collapsed later (checkbox checked event) I crash saying something is null. Same thing if I try to set isenabled or anything else. I would think it was a scope problem but it is declared in wpf so it should be available to all code in the codebehind right? If that was the problem then I shouldn't have been able to populated the list from codebehind either as far as I know.

Any thoughts?

Quote:

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Originally Posted by pmeloy

I crash saying something is null.

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The first thing to do is work out what is null. That's what you have a debugger for. Once you know what is null, then you can work backwards to work out why.

No idea what is null. The exception shows up at the title of the wpf page

Code:

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<Window x:Class="AdminProfitLoss"

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BUT, you twigged a thought so I added a "loading" variable that is true at startup and false after the loading is complete and ignored any settings while it is true. Now it works fine!
I guess it was a case of the combobox not being created before the form_load was being run. I had thought the WPF code was loaded first but I guess not