I am using a CheckComboBox within a ListView/GridView column, defined as follows...
```
<GridViewColumn Header="Surcharges">
<GridViewColumn.CellTemplate>
<DataTemplate>
<et:CheckComboBox Delimiter=" " DisplayMemberPath="PalletNetworkSurchargeCode" ItemsSource="{Binding Path=SurchargeOptions}" MinWidth="100" SelectedValue="{Binding Path=Surcharges}" ValueMemberPath="PalletNetworkSurchargeCode" Width="100" />
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
```
Within the View Model, SurchargeOptions is a List<PalletNetworkSurcharge>, PalletNetworkSurcharge.PalletNetworkSurchargeCode is a String, and SurchargeOptions is also a String.
If the user scrolls the list (quickly), or resizes the form in such a way that one or more items in the list is no longer visible, when that item is made visible again (either by more scrolling or more resizing) any items selected in the CheckComboBox are no longer selected and the clearing of the selected items is also reflected in the bound "SelectedValue".
Can you please help. Am I missing something within the Xaml or is there a problem with the control?
Thanks.
Martin.
Comments: ** Comment from web user: MartinRobins **
```
<GridViewColumn Header="Surcharges">
<GridViewColumn.CellTemplate>
<DataTemplate>
<et:CheckComboBox Delimiter=" " DisplayMemberPath="PalletNetworkSurchargeCode" ItemsSource="{Binding Path=SurchargeOptions}" MinWidth="100" SelectedValue="{Binding Path=Surcharges}" ValueMemberPath="PalletNetworkSurchargeCode" Width="100" />
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
```
Within the View Model, SurchargeOptions is a List<PalletNetworkSurcharge>, PalletNetworkSurcharge.PalletNetworkSurchargeCode is a String, and SurchargeOptions is also a String.
If the user scrolls the list (quickly), or resizes the form in such a way that one or more items in the list is no longer visible, when that item is made visible again (either by more scrolling or more resizing) any items selected in the CheckComboBox are no longer selected and the clearing of the selected items is also reflected in the bound "SelectedValue".
Can you please help. Am I missing something within the Xaml or is there a problem with the control?
Thanks.
Martin.
Comments: ** Comment from web user: MartinRobins **
It would appear that the control behaves as expected if the [VirtualizingPanel.IsVirtualizing Attached Property](https://msdn.microsoft.com/query/dev12.query?appId=Dev12IDEF1&l=EN-US&k=k(System.Windows.Controls.VirtualizingPanel.IsVirtualizing);k(VS.XamlEditor);k(TargetFrameworkMoniker-.NETFramework,Version%3Dv4.5.1)&rd=true) is set to false. This leads me to believe that the control is for some reason updating the bound SelectedValue when the control is destroyed due to being no longer in view.
Don't know if that helps, but bearin in mind that the default value for the VirtualizingPanel.IsVirtualizing Attached Property is true this could continue to be a significant problem when using the control within an ItemsControl.
Martin.