[Solved] Don't Show MultiColumnComboBox Validation

1 Answer 27 Views

GridView MultiColumnComboBox

Shawn asked on 31 Mar 2026, 08:45 PM

CleanShot-2026-03-31-at-13-41-05.png

I'm using the RadMultiColumnComboBox control with the GridViewItemsSourceProvider. It's showing a validation error that something "cannot be empty" and I can't get it to go away. Because this control is just used to select a record, I don't want any kind of validation in the grid of any kind. I've tried setting these properties on the bindings for each column:

ValidatesOnDataErrors = false,
ValidatesOnNotifyDataErrors = false,
ValidatesOnExceptions = false,
NotifyOnValidationError = false,

I've also tried setting the grid view's validation mode to none. I've tried setting these properties on the columns:

IsReadOnly = true,
ValidatesOnDataErrors = Telerik.Windows.Controls.GridViewValidationMode.None

Nothing works.

1 Answer, 1 is accepted

Accepted

answered on 03 Apr 2026, 07:41 AM

multicolumncomboboxvalidation.zip

Hello, Shawn,

You can use ValidatesOnDataErrors property to prevent validation. I attached a sample project with RadMultiColumnComboBox and GridViewItemsSourceProvider:

<telerik:RadMultiColumnComboBox DisplayMemberPath="Name" VerticalAlignment="Center" SelectedItem="{Binding SelectedItem, Mode=TwoWay, ValidatesOnDataErrors=False}" Margin="200,0,76,0">
    <telerik:RadMultiColumnComboBox.Resources>
        <Style TargetType="telerik:RadGridView">
            <Setter Property="ValidatesOnDataErrors" Value="None"/>
        </Style>
    </telerik:RadMultiColumnComboBox.Resources>
    <telerik:RadMultiColumnComboBox.ItemsSourceProvider>
        <telerik:GridViewItemsSourceProvider ItemsSource="{Binding Employees}"/>
    </telerik:RadMultiColumnComboBox.ItemsSourceProvider>
</telerik:RadMultiColumnComboBox>

As RadMultiColumnComboBox internally hosts RadGridView in the popup, you can chech the following documentation for validation: WPF RadGridView Features Validating - Telerik UI for WPF

In case you have different setup and need further assistance, it would be great if you can modify the provided project and demonstrate there the exact case that you have.

I hope this helps. Let me know if you have any other questions.

Regards,
Nadya | Tech Support Engineer
Progress Telerik

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