Fix issue with setting SelectedItem on TreeView would crash application #3136
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msft-github-bot
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| @@ -264,7 +264,7 @@ void TreeView::OnPropertyChanged(const winrt::DependencyPropertyChangedEventArgs | |||
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| const auto items = SelectedItems(); | |||
| const auto selected = items.Size() > 0 ? items.GetAt(0) : nullptr; | |||
| const auto selected = (items != nullptr && items.Size() > 0) ? items.GetAt(0) : nullptr; | |||
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items != nullptr [](start = 31, length = 16)
Under what circumstances is this null?
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It seems that SelectedItems returns null when TreeView can't resolve it's listcontrol.
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and what causes that to happen?
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SelectedItems returns null if the internal listview can't be found or the listviews ListViewModel can't be found. So in #3129, we probably crashed due to the binding resolving before the template was applied leaving us in a state where we did not have a listview or selectionmodel.
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/azp run |
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StephenLPeters
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@chingucoding can you merge master to pick up the CI build fix that just went in? |
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@StephenLPeters This and all other opens PR I created are up to date now. |
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/azp run |
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Azure Pipelines successfully started running 1 pipeline(s). |
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/azp run |
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Azure Pipelines successfully started running 1 pipeline(s). |
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Any ETA on when this will be available? |
@sis2004 I just merged this into the repository so it will be included in the next versions. I'd guess there will be a prerelease version made during September, when it is the bot will post on the original issue that it was included in the package. |
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@StephenLPeters thanks, I'll keep an eye out for it. |
marcelwgn
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Description
The issue is that
SelectedItemmight be null in some cases which we didn't anticipate. Added a nullcheck to the selecteditems to guard against this.The brackets were added to improve readability.
Motivation and Context
Fixes #3129
How Has This Been Tested?
Add new API test.
Screenshots (if appropriate):