Last Updated: 14 Feb 2024 16:26 by Stenly
When a value is pasted in the RadMultiColumnComboBox control without opening the typing in it (or opening the drop-down via the button), it will not be selected when navigating to the next control using the Tab key. Even if the value is present in the bound collection.
Last Updated: 25 Jan 2024 19:04 by ADMIN
Release LIB 2023.3.1315 (15 Jan 2024)
When the SelectedBoxesVisiblity property is set to Collapsed and the SelectedItem is bound, no text appears in the control when an item is select.
Last Updated: 25 Jan 2024 19:04 by ADMIN
Release LIB 2023.3.1315 (15 Jan 2024)
GridViewMultiColumnComboBoxColumn does not have any selected value in edit mode when SelectionBoxesVisibility is set to Collapsed/Hidden and AutoCompleteMode is Search/Suggest.
Last Updated: 31 Oct 2023 13:36 by ADMIN
Item is automatically changed when pressing the tab key to leave the control
Last Updated: 20 Oct 2023 12:49 by ADMIN
Release LIB 2023.3.1023 (23 Oct 2023)
System.InvalidOperationException: 'Collection was modified; enumeration operation may not execute.' - This exception is occasionally thrown while searching in the MultiColumnComboBox after populating the FilterDescriptors/GroupDescriptors of the RadGridView programmatically. 
Last Updated: 28 Sep 2023 06:55 by ADMIN
Release R3 2023
Item is automatically selected when pressing the tab key to leave the control.
Last Updated: 23 May 2023 07:29 by ADMIN
Release R2 2023
Setting the Mode to OneWay of the Binding instance for the SelectedItem property does not update the UI when the bound property's value is updated.
Last Updated: 23 May 2023 05:50 by ADMIN
Release R2 2023
When the KeepDropDownOpen property is False, a ContextMenu set on the RadGridView in the drop down does not open. 
Last Updated: 07 Mar 2023 13:57 by ADMIN
Release R1 2023 SP1
If you have two or more instances of GridViewItemsSourceProvider that you switch at runtime, their columns get cleared on the second switch. This happens because when the ItemsSourceProvider of RadMultiColumnComboBox changes, the columns of the old GridViewItemsSourceProvider get cleared. So, you cannot use the old provider anymore, unless you add the columns again manually.

To resolve this, use a new instance of GridViewItemsSourceProvider, each time you change the ItemsSourceProvider property.
Last Updated: 20 Feb 2023 08:18 by ADMIN

When biding IsVisible of column in RadMultiColumnComboBox/GridViewItemsSourceProvider using MVVM pattern, the binding won't work initially, but is works as expected if removing the ElementName and adding it back in the below example xaml using debugger.

PS1. The binding for CheckBox(in the below sample) works with issue but not for RadMultiColumnComboBox

PS2. Also attached full sample code.

<Window x:Class="TestProject.MainWindow"
                Title="MainWindow" Height="350" Width="525">
    <Grid Margin="0,0,0,20" x:Name="rootGrid">
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>

        <Button Grid.Row="0" Command="{Binding ToggleCmd}">Toggle Last Name Visible</Button>
        <CheckBox Grid.Row="1" IsChecked="{Binding IsLastNameVisible}">Is Last Name Visible</CheckBox>

        <telerik:RadMultiColumnComboBox Grid.Row="2">
                <telerik:GridViewItemsSourceProvider ItemsSource="{Binding AllClubs}" AutoGenerateColumns="false" >
                        <telerik:GridViewDataColumn DataMemberBinding="{Binding FirstName}"   />
                        <telerik:GridViewDataColumn DataMemberBinding="{Binding LastName}"
                                                    IsVisible="{Binding DataContext.IsLastNameVisible , ElementName=rootGrid}" />


Last Updated: 03 Feb 2023 12:56 by ADMIN
Release LIB 2023.1.206 (6 Feb 2023)

NotImplementedException is thrown if the ItemsSourceProvider property is set in a Style setter.

To work this around, implement custom GridViewItemsSourceProvider and override its CreateInstanceCore method.

public class CustomGridViewItemsSourceProvider : GridViewItemsSourceProvider
	protected override Freezable CreateInstanceCore()
		return new CustomGridViewItemsSourceProvider();

Last Updated: 21 Oct 2022 14:33 by ADMIN
Release LIB 2022.3.1024 (24 Oct 2022)
When the dropdown menu is opened, clicking on a scrollbar (either horizontal or vertical) to review other cells automatically closes the menu. This behavior is present when the KeepDropDownOpen is false.
Last Updated: 31 Aug 2022 12:47 by ADMIN
Release LIB 2022.2.905 (05 September2022)

If you set the KeepDropDownOpen property of RadMultiColumnComboBox to False, clicking outside of the control should close the popup showing the dropdown content. This stops working after you drag a row from the GridView outside of the dropdown. For example, the drop can happen outside of the RadMultiColumnComboBox control or on its text input and drop down button area.

To resolve this, you can subscribe to the PreviewMouseLeftButtonUp event of RadMultiColumnComboBox and capture the mouse when needed.

this.mccb.AddHandler(RadMultiColumnComboBox.PreviewMouseLeftButtonUpEvent, new MouseButtonEventHandler(Mccb_MouseLeftButtonUp), true);
private void Mccb_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
	var button = Mouse.DirectlyOver as RadDropDownButton;
	if (this.mccb.IsDropDownOpen && button != null && button.TemplatedParent is RadMultiColumnComboBox)
		Dispatcher.BeginInvoke(new Action(() => { button.CaptureMouse(); }));

Last Updated: 18 Jul 2022 08:52 by ADMIN
Release LIB 2022.2.718 (18 July 2022)

The value of the SelectedItem is shown twice when the theme is changed.

A temporary solution to this would be to revert to the 2022.2.511 version.

Last Updated: 11 Jul 2022 06:55 by ADMIN
Release LIB 2022.2.711 (11 July 2022)

The text of the text input box is automatically assigned if SelectedItem is set initially. This should happen when the SelectionBoxesVisibility property is set to Visible (which is the default value). For example, if you have an item called "Item A" and you assign it to the SelectedItem property at startup of the control, then the text will also become "Item A".

To work this around, you can manually clear the text on loaded of the control.

private void RadMultiColumnComboBox_Loaded(object sender, RoutedEventArgs e)
	var mccb = (RadMultiColumnComboBox)sender;	
	var tb = mccb.FindChildByType<TextBox>();
	tb.Text = string.Empty;

Last Updated: 16 Jun 2022 12:06 by ADMIN
Release R2 2022 SP1
The issue reproduces if you set the SelectedItem of the RadMultiColumnComboBox control before its textbox is loaded. One way for this situation to occur is if you data bind the SelectedItem to a property of the view model and then assign to the view model to the DataContext of the view, before the InitializeComponent call.

To work this around, you can reset the SelectedItem property on Loaded.

private void RadMultiColumnComboBox_Loaded(object sender, RoutedEventArgs e)
	var mccb = (RadMultiColumnComboBox)sender;            
	var selection = mccb.SelectedItem;
	mccb.SetCurrentValue(RadMultiColumnComboBox.SelectedItemProperty, null);
	mccb.SetCurrentValue(RadMultiColumnComboBox.SelectedItemProperty, selection);
Last Updated: 30 May 2022 09:14 by ADMIN
Release LIB 2022.2.530 (30 May 2022)

When the SelectionMode of MultiColumnComboBox is set to Single, changing the Selection invokes twice the SelectionChanged event.

What I would expect is that the event fires only once, with one item in AddedItems and one item in RemovedItems. Currently, addition and removal is done seperately, and the two invocations of the event correspond to them.

To reproduce, just use the Getting Started article about MultiColumnComboBox with the Clubs ItemSource. Subscribe to SelectionChanged event and make a change to the selection. I hope the following gif makes this clear - the first selection is valid, but the second should invoke the event only once, with 1 item added, 1 removed.

Last Updated: 07 Jan 2022 07:09 by ADMIN
Release R1 2022

The drop-down menu does not close when a context menu is opened on top of it, even if the KeepDropDownOpen="False". The control would need to move the focus in order for the drop-down to close.

To work this around, you can use the CloseDropDown() method of the MultiColumnComboBox control.

Last Updated: 20 Sep 2021 07:04 by ADMIN
Release LIB 2021.3.920 (20 Sep 2021)
The search text gets cleared when a click on the combobox occurs (to open a combobox). No selection is performed during this action.

To work this around, you can cache the search text just before it is cleared and then restore it after the selection is performed.
Last Updated: 02 Aug 2021 08:02 by ADMIN
Release LIB 2021.2.802 (2 Aug 2021)

When placing controls in the CellTemplate/CellEditTemplate in the RadMultiColumnComboBox`s dropdown`s GridView some do not receive/accept the mouse input correctly.

In the newest version (2021.2.615) the dropdown of a RadDatePicker does not open. A RadButton works fine and a RadComboBox open and can select an item via mouse click.

In a previous version (2021.1.325) the RadComboBox also does not work, this seems to be fixed already.


I have attached a sample project demonstrating the behavio:

1) start the project

2) open the dropdown of the RadMultiColumnComboBox

3) click on the RadDatePicker`s calender icon button. => the calender view does not open

The very same DataTemplate is applied obove the RadMultiColumnComboBox to illustrate the proper behavior in contrast.


The behavior is visually demonstrated in the .gif (1.gif and 2.gif) I have attached.

1 2