DataGrid Memory Leak

Describe the bug DataGrid keeps a NotifyCollectionChangedEventHandler open on Items when Items is bound to a view model even after its removed from logic/visual tree. Memory leak happens when view model is not eligible to be garbage collected. I have a singleton view model that I bind to a new view instance every time the user navigates to the page.

Because of this open handle, DataGrid is never disposed, causing thousands of Shapes.Rectangle instances to survive GC.

To Reproduce

• Create a view model with an ObservableCollection of any type, populate it with a generous amount of items upon view model construction
• Create instance of view model that is referenced as a singleton (making it ineligible for garbage collection)
• Create a view with DataGrid, bind Items to view model’s ObservableCollection, create dummy columns so that rows will be rendered.
• Create presentation that instantiates a new view for every navigation, DataContext being set to the same view model
• Navigate between view in question and elsewhere, thereby causing a new view to be instantiated and bound to view model. Repeat this a few times.
• Observe memory leak

Expected behavior Memory leak does not occur.

Screenshots Screenshot of Instance Retention Graph created using Redgate Ants Profiler. This graph indicates surviving objects AFTER the view has been destroyed and successfully GC’d. Note WindchimeDataGrid is my own inheritance of DataGrid, however it only contains 10 lines of code to modify selection behavior and I’ve recreated this bug with the normal DataGrid.

Also note my view model at the top, which is referenced ultimately as a single instance in my DI Container.

Desktop : Windows 10,0.19044

[jhimes144]

@timunie Thanks for asking! I’m all set, setting the collection to null fixes the issue. I accidently closed with comment, I’ll let you guys do that.

[adirh3]

@jhimes144 I experienced similar issue, and this fixed it - https://github.com/AvaloniaUI/Avalonia/pull/7948 Doesn’t seemed to be backported into 0.10.x, did you check with 11-previews?