Description

When items are removed from a CollectionView, or when a DataTemplateSelector switches templates (making certain item templates no longer active), the handlers for controls within those templates are not properly disconnected. This results in memory leaks as the controls and their handlers remain in memory.

Scenario 1: DataTemplateSelector switching templates

1. Create a CollectionView with a DataTemplateSelector that switches between two templates based on item state
2. Initially render some items with Template A
3. Change the item state so all items now use Template B (Template A is no longer used)
4. Observe that handlers for controls in Template A instances remain connected

Scenario 2: Removing items from CollectionView

1. Create a CollectionView with items
2. Remove items from the ObservableCollection (using RemoveAt(), Remove(), or Clear())
3. Observe that handlers for controls in the removed items remain connected

Expected Behavior

When a CollectionView item is removed or its template is no longer used, all handlers for controls within that item's template should be automatically disconnected via OnHandlerChanged() being called with a null handler.

Actual Behavior

Handlers remain connected indefinitely. The controls remain in memory and cannot be garbage collected, leading to memory leaks. Only recently created items have their handlers disconnected; older items keep their handlers connected.

Steps to Reproduce

1. Clone https://github.com/Vetle444/MauiTestApp/tree/collectionViewItemHandler
2. Make sure to be on branch collectionViewItemHandler
3. Build and deploy app
4. Navigate to CollectionView Template Handler Test
5. Click "Switch to all Template B"
6. Navigate back
7. Click Show Labels With Connected Handlers
8. Observe that the items that were removed did not have their handler disconnected

Link to public reproduction project repository

https://github.com/Vetle444/MauiTestApp/tree/collectionViewItemHandler

Version with bug

9.0.110 SR12

Is this a regression from previous behavior?

Yes, this used to work in Xamarin.Forms

Last version that worked well

No response

Affected platforms

Android

Affected platform versions

No response

Did you find any workaround?

Some way to disconnect it manually

Relevant log output