ComboBoxFilteringBehavior doesn't work with VirtualizingStackPanel

[Aleksandar]

I've implemented a custom ComboBoxFilteringBehavior but the list won't filter. Looks like it's because I'm using a VirtualizingStackPanel to improve rendering performance of list that contains 1,000+ items. How can I filter the ComboBox list and continue to use the VirtualizingStackPanel?

[Martin Ivanov]

Hello Aleksandar,

Filtering is not supported when the control is virtualized. This is mentioned at the den of the Filtering article. I am afraid that currently, there is no customization via RadComboBox's API that will allow you to use both filtering and UI virtualization.

A possible approach that you can try is to subscribe to the text changed event of the TextBox presenting the RadComboBox input and when the Text property of RadComboBox is changed, to manually filter the ItemsSource of the control.

If you have other questions, please let me know.

Regards,
Martin Ivanov
Progress Telerik

[Aleksandar]

I've switched to the RadAutoCompleteBox and it's working better now. I didn't see in the documentation if there was a way to turn on virtualization manually or if it's on by default.

[Martin Ivanov]

Hello Aleksandar,

RadAutoCompleteBox uses RadListBox to show its items. The listbox's UI virtualization is enabled by default.

I hope this helps.

Regards,
Martin Ivanov
Progress Telerik