dotnet/Documentation/compatibility/items_clear-does-not-remove-duplicates-from-selecteditems.md

Items.Clear does not remove duplicates from SelectedItems

Scope

Minor

Version Introduced

4.5

Version Reverted

4.6.2

Source Analyzer Status

NotPlanned

Change Description

Suppose a Selector (with multiple selection enabled) has duplicates in its SelectedItems collection - the same item appears more than once. Removing those items from the data source (e.g. by calling Items.Clear) fails to remove them from SelectedItems; only the first instance is removed. Furthermore, subsequent use of SelectedItems (e.g. SelectedItems.Clear()) can encounter problems such as ArgumentException, because SelectedItems contains items that are no longer in the data source.

• Quirked
• Build-time break

Recommended Action

Upgrade if possible to .NET 4.6.2.

Affected APIs

• P:System.Windows.Controls.Primitives.MultiSelector.SelectedItems

Category

Windows Presentation Foundation (WPF)