DataForm DataFormComboBoxField SelectedItem Becomes Null After Commit Button Click

Updated on Sep 15, 2025

Environment

Product Version
Product	RadDataForm for WPF

Description

The following setup produces a null value in the SelectedItem of the RadDataFormComboBoxField on Commit button click.

XAML

	<telerik:DataFormComboBoxField DataMemberBinding="{Binding SelectedItem}"
								   ItemsSource="{Binding Items}" />

This happens if the Commit button unloads the control from the visual tree. For example, if hosted in dialog window that gets closed on commit.

Solution

To resolve this, add a RadComboBox control directly inside of the Content of the data field.

XAML

	<telerik:DataFormComboBoxField>
		<telerik:RadComboBox SelectedItem="{Binding SelectedItem}" 
							 ItemsSource="{Binding Items}"  />
	</telerik:DataFormComboBoxField>