dotnet/Documentation/compatibility/accessing-a-wpf-datagrid's-selected-items-from-a-handler-of-the-datagrid's-unloadingrow-event-can-cause-a-nullreferenceexception.md

Accessing a WPF DataGrid's selected items from a handler of the DataGrid's UnloadingRow event can cause a NullReferenceException

Scope

Minor

Version Introduced

4.5

Version Reverted

4.6

Source Analyzer Status

Planned

Change Description

Due to a bug in the .NET Framework 4.5, event handlers for xref:System.Windows.Controls.DataGrid events involving the removal of a row can cause a xref:System.NullReferenceException?displayProperty=name to be thrown if they access the xref:System.Windows.Controls.DataGrid's xref:System.Windows.Controls.Primitives.Selector.SelectedItem?displayProperty=name or xref:System.Windows.Controls.Primitives.MultiSelector.SelectedItems?displayProperty=name properties.

• Quirked
• Build-time break

Recommended Action

This issue has been fixed in the .NET Framework 4.6 and may be addressed by upgrading to that version of the .NET Framework.

Affected APIs

• E:System.Windows.Controls.DataGrid.UnloadingRow
• E:System.Windows.Controls.DataGrid.UnloadingRowDetails

Category

Windows Presentation Foundation (WPF)