Last Updated: 24 Dec 2019 12:00 by ADMIN

The Validation.ErrorTemplate attached property is not set. To workaround this, you can use the following resource.

<ControlTemplate x:Key="ValidationTooltipTemplate">
    <Grid SnapsToDevicePixels="True" VerticalAlignment="Top">
        <Border Background="Transparent" HorizontalAlignment="Right" VerticalAlignment="Top" Width="3" Height="3"/>
        <AdornedElementPlaceholder x:Name="Holder"/>
        <Border BorderBrush="{StaticResource ValidationTooltipOuterBorder}" BorderThickness="1" CornerRadius="{StaticResource ValidationTooltip_CornerRadius}"/>
        <Path Data="M2,1 L6,1 6,5 Z" Fill="{StaticResource ValidationInnerTick}" Width="7" Height="7" HorizontalAlignment="Right" VerticalAlignment="Top"/>
        <Path Data="M0,0 L2,0 7,5 7,7 Z" Fill="{StaticResource ValidationOuterTick}" Width="7" Height="7" HorizontalAlignment="Right" VerticalAlignment="Top"/>
            <ToolTip x:Name="PART_ToolTip"
                DataContext="{Binding RelativeSource={RelativeSource Mode=Self}, Path=PlacementTarget.DataContext}"
                Template="{StaticResource ErrorTooltipTemplate}"

<Style TargetType="telerik:RadMultiColumnComboBox" BasedOn="{StaticResource RadMultiColumnComboBoxStyle}">
    <Setter Property="Validation.ErrorTemplate" Value="{StaticResource ValidationTooltipTemplate}" />

Last Updated: 09 Dec 2019 11:43 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: 18 Nov 2019 11:55 by ADMIN
Release LIB 2019.3.1118 (11/18/2019)
Dropdown does not close when OpenDropDownOnFocus is True and KeepDropDownOpen is False and the user has previously made a selection after opening the control by clicking on its textbox part.
Last Updated: 15 Nov 2019 14:03 by ADMIN
Release LIB 2019.3.1118
A NullReferenceException is thrown after opening the dropdown and there is an implicit style targeting RadGridView which sets the SearchMode property.
Last Updated: 13 Nov 2019 11:47 by ADMIN

The following error is thrown when the dropdown of the control is opened: Cannot find governing FrameworkElement or FrameworkContentElement for target element. ... ; target element is 'GridViewItemsSourceProvider; target property is 'ItemsSource' (type 'Object')

If the combobox is placed inside a RadGridView, the error is thrown each time the dropdown is opened (after a commit action).

Last Updated: 11 Nov 2019 14:24 by ADMIN
InvalidOperationException is thrown when programmatically adding items to the SelectedItems collection after the dropdown has been opened.
Last Updated: 07 Nov 2019 11:02 by ADMIN
Created by: Mats
Comments: 3
Category: MultiColumnComboBox
Type: Bug Report

Hi Telerik-Team,


i found a bug similar to forum post, but not the same.

In MultiColumnComboBox when SelectionBoxesVisibility is set  to 'collapsed' and and whatever you set AutoCompleteMode to (different from the forum post),

if you select the first item it is not shown. Although the NullText is removed. It works perfectly for all the other items. This is quiet a problem if you only have one item in the dropwdown :D




Last Updated: 23 Oct 2019 11:38 by ADMIN
Created by: Franz
Comments: 0
Category: MultiColumnComboBox
Type: Feature Request
The selection is lost when sorting or filtering is applied and the control is already filtered.
Last Updated: 27 Sep 2019 15:47 by ADMIN
Created by: Michael
Comments: 0
Category: MultiColumnComboBox
Type: Feature Request
Add grouping support in the GridView element.
Last Updated: 02 Aug 2019 10:32 by ADMIN
Release LIB 2019.2.805 (8/05/2019)

If set the AutoCompleteMode property in a Style Setter, and exception is thrown.

To work this around set the property directly on the control.
<telerik:RadMultiColumnComboBox AutoCompleteMode="Search" />

Last Updated: 22 Jul 2019 06:02 by ADMIN
Created by: Tino
Comments: 3
Category: MultiColumnComboBox
Type: Feature Request
Add option to hide row indicator in grid.
Last Updated: 07 May 2019 09:57 by ADMIN
Release R2 2019
Last Updated: 03 Apr 2019 08:36 by ADMIN
Create API which can change the selected item when only using the Up/Down keys of the keyboard.
Last Updated: 25 Mar 2019 11:39 by ADMIN
RadGridView columns expose a IsSearchable property that is not taken into account when you use RadMultiColumnComboBox and search via the autocomplete box. Add support for the property. If set to False, the searching should not find the corresponding column.
Last Updated: 22 Mar 2019 12:49 by ADMIN
Created by: Stefan
Comments: 1
Category: MultiColumnComboBox
Type: Feature Request
the multicolumncombobox has this weird display with X buttons which is completely inconsistent with a combo box.  Potentially make sense when you are multi-selecting but single select I would like to operate in the same way as a rad combo box so the user doesn't see any difference.
Last Updated: 18 Mar 2019 12:17 by ADMIN
Created by: Huan jia
Comments: 0
Category: MultiColumnComboBox
Type: Feature Request
 Expose DropDownOpened and DropDownClosed events similarly to the RadComboBox control.
Last Updated: 07 Mar 2019 09:32 by ADMIN

The RadMultiColumnComboBox has a separate keyboard functionality executed when the watermark textbox (the search box) is focused and the dropdown is open. Basically, you can navigate through the rows of the gridview part and select them using the keyboard. 

Currently, this functionality is private. Introduce an API that allows you to customize the keyboard navigation. Consider something similar to the KeyboardCommandProvider of RadGridView.

Last Updated: 16 Feb 2019 10:24 by ADMIN
If you set the SelectionMode of the control to Multiple the SelectionChanged event fires only when you select item for the first item. Each next selection won't fire the event.

To work this around use to CollectionChanged event of the SelectedItems collection of RadMultiColumnComboBox.
Last Updated: 15 Feb 2019 14:25 by ADMIN
Created by: Alexander
Comments: 2
Category: MultiColumnComboBox
Type: Bug Report

Hello Telerik,

Exception is thrown after typing in the autocompletebox and selecting an item right after that. 

  Message=Exception has been thrown by the target of an invocation.
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
   at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
   at System.Delegate.DynamicInvokeImpl(Object[] args)
   at System.Windows.RoutedEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
   at Telerik.Windows.Controls.GridView.GridViewDataControl.RaiseSelectionChangedEvent(SelectionChangeEventArgs args)
   at Telerik.Windows.Controls.DataControl.RaiseSelectionChangedEvent(ItemSelectionChange selectionChange)
   at Telerik.Windows.Controls.DataControl.Telerik.Windows.Data.Selection.ISelectorInternal.RaiseSelectionChangedEvent(ItemSelectionChange selectionChange)
   at Telerik.Windows.Data.Selection.ItemSelectionHandler.EndAllowedSelection(ItemSelectionChange selectionChange)
   at Telerik.Windows.Data.Selection.ItemSelectionHandler.EndPendingSelection(ItemSelectionChange pendingSelection)
   at Telerik.Windows.Data.Selection.ItemSelectionHandler.EndSelection()
   at Telerik.Windows.Data.Selection.ItemSelectionHandler.SelectedItems_CollectionChanged(Object sender, 

Thanks in advance.


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