In Development
Last Updated: 04 Dec 2023 14:13 by ADMIN
When the SelectedBoxesVisiblity property is set to Collapsed and the SelectedItem is bound, no text appears in the control when an item is select.
In Development
Last Updated: 04 Dec 2023 14:12 by ADMIN
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: 27 Oct 2023 14:53 by Stenly
We could include an option for the RadMultiColumnComboBox to behave similarly to an editable and read-only RadComboBox.
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: 28 Aug 2023 15:16 by ADMIN
Currently, when a RadMultiColumnComboBox is placed in a ScrollViewer, the inner ScrollViewer of RadMultiColumnComboBox prevents the parent one from scrolling via the mouse wheel.

Add an option or change the default behavior and allow the scrolling to bubble to the parent scrollbar. This behavior can be observed in the native TextBox control with an enabled vertical scrollbar.

For the time being, the MouseWheel event can be manually raised:
private void ScrollViewer_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
	if (sender is ListBox && !e.Handled)
		e.Handled = true;
		var eventArg = new MouseWheelEventArgs(e.MouseDevice, e.Timestamp, e.Delta);
		eventArg.RoutedEvent = UIElement.MouseWheelEvent;
		eventArg.Source = sender;
		var parent = ((Control)sender).Parent as UIElement;
Last Updated: 25 Aug 2023 20:52 by Martin Ivanov
Currently, when DataContext of RadMultiColumnComboBox changes to an object that contains valid SelectedItem and ItemsSource view model properties, the SelectedItem get set to null. This happens because the control resets the selection on ItemsSource changed, which happens after the SelectedItem binding was evaluated. 

Add an option to ensure that the SelectedItem won't get reset after the binding was evaluated  because of the ItemsSource changed action. The behavior should mimic how RadComboBox behaves in this scenario.
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.

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