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).

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"/>
        <ToolTipService.ToolTip>
            <ToolTip x:Name="PART_ToolTip"
                DataContext="{Binding RelativeSource={RelativeSource Mode=Self}, Path=PlacementTarget.DataContext}"
                Template="{StaticResource ErrorTooltipTemplate}"
                Placement="Right"/>
        </ToolTipService.ToolTip>
    </Grid>
</ControlTemplate>

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

GridViewMultiColumnComboBoxColumn does not have any selected value in edit mode when SelectionBoxesVisibility is set to Collapsed/Hidden and AutoCompleteMode is Search/Suggest.

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.

A NullReferenceException is thrown after opening the dropdown and there is an implicit style targeting RadGridView which sets the SearchMode property.

InvalidOperationException is thrown when programmatically adding items to the SelectedItems collection after the dropdown has been opened.

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

 

Regards,

Mats

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" />

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.

Hello Telerik,

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

Thanks in advance.

 

The event should fire when the DropDownContentManager gets initialized.

To work this around use the InitializeSelectionBridge event. The DropDownContentManager is initialized when this event fires.

Hello,

 

when selecting more items and dropdown positioning is down and input filed has fixed width, the dropdown covers the input field.

It should move down to the bottom edge of input field.