The functionality is documented at http://docs.telerik.com/devtools/wpf/controls/radgridview/filtering/icolumn-filter-descriptors and for the time being the functionality can be achieved by implementing an attached behavior. 

If you have a RadComboBox inside a ControlPanelItem, when you open the RadComboBox's dropdown and select an item, the ControlPanelItem is not closed. As a workaround, you can manually capture the mouse. Please check the attached project.

WinForms: http://www.telerik.com/help/winforms/gridview-grouping-setting-groups-programmatically.html

You can find our online documentation on a detailed information on the currently supported grouping:
http://docs.telerik.com/devtools/wpf/controls/radgridview/grouping/basics.html

As a workaround, the Path with the PathGeometry setter in the style can be replaced by a RadGlyph with a pin icon. The IsPinned Trigger in the style can be replaced with a DataTrigger to the parent row's IsPinned. Here's an example of the updated style for the Fluent theme:

<Style x:Key="GridViewPinButtonStyle" TargetType="grid:GridViewPinButton">
        <Setter Property="PathStyle" Value="{StaticResource PinUnpinPathStyle}"/>
        <Setter Property="Foreground" Value="{telerik1:FluentResource ResourceKey=IconBrush}"/>
        <Setter Property="MinHeight" Value="28"/>
        <Setter Property="MinWidth" Value="22"/>
        <Setter Property="IsBackgroundVisible" Value="False"/>
        <Setter Property="Command" Value="{x:Static telerik:RadGridViewCommands.TogglePinnedRowState}"/>
        <Setter Property="CommandParameter" Value="{Binding}"/>
        <Setter Property="SnapsToDevicePixels" Value="True"/>
        <Setter Property="BorderThickness" Value="0"/>
        <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
        <Setter Property="VerticalContentAlignment" Value="Stretch"/>
        <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
        <Setter Property="IsTabStop" Value="False"/>
        <Setter Property="Padding" Value="0 0 2 0"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="telerik:RadPathButton">
                    <Grid Background="Transparent">
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="BackgroundVisibility">
                                <VisualState x:Name="BackgroundIsHidden">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="OuterBorder" Storyboard.TargetProperty="Visibility">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <Visibility>Collapsed</Visibility>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="BackgroundIsVisible"/>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <Border x:Name="OuterBorder"
                                BorderThickness="{TemplateBinding BorderThickness}"
                                BorderBrush="{TemplateBinding BorderBrush}"
                                Background="{TemplateBinding Background}"
                                CornerRadius="{TemplateBinding CornerRadius}"/>
                        <telerik:RadGlyph x:Name="UnPinIcon" Foreground="{TemplateBinding Foreground}" FontSize="16" HorizontalAlignment="Center" VerticalAlignment="Center" Glyph="{StaticResource GlyphPin}"/>
                    </Grid>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter Property="Foreground" Value="{telerik1:FluentResource ResourceKey=AccentMouseOverBrush}"/>
                        </Trigger>
                        <Trigger Property="IsPressed" Value="True">
                            <Setter Property="Foreground" Value="{telerik1:FluentResource ResourceKey=AccentPressedBrush}"/>
                        </Trigger>
                        <DataTrigger Binding="{Binding IsPinned, RelativeSource={RelativeSource AncestorType=telerik:GridViewRow}}" Value="True">
                            <Setter TargetName="UnPinIcon" Property="Glyph" Value="{StaticResource GlyphUnpin}" />
                        </DataTrigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

ArgumentException: 'RadGlyphExtension' is not valid for Setter.Value. The only supported MarkupExtension types are DynamicResourceExtension and BindingBase or derived types.

StackTrace:
   at System.Windows.Setter.Seal()
   at System.Windows.SetterBaseCollection.Seal()
   at System.Windows.Style.Seal()
   at System.Windows.Style.Seal()
   at System.Windows.StyleHelper.UpdateStyleCache(FrameworkElement fe, FrameworkContentElement fce, Style oldStyle, Style newStyle, Style& styleCache)
   at System.Windows.FrameworkElement.OnStyleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   at System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp, Boolean preserveCurrentValue)
   at System.Windows.FrameworkElement.UpdateStyleProperty()
   at System.Windows.FrameworkElement.OnInitialized(EventArgs e)
   at Telerik.Windows.Controls.RadButton.OnInitialized(EventArgs e)
   at Telerik.Windows.Controls.RadPathButton.OnInitialized(EventArgs e)
   at Telerik.Windows.Controls.GridView.GridViewPinButton.OnInitialized(EventArgs e)
   at System.Windows.FrameworkElement.TryFireInitialized()
   at System.Windows.FrameworkElement.EndInit()
   at MS.Internal.Xaml.Runtime.ClrObjectRuntime.InitializationGuard(XamlType xamlType, Object obj, Boolean begin)

In the following scenario:

<telerik:RadGridView x:Name="clubsGrid" ItemsSource="{Binding Foos}" AutoGenerateColumns="False">
	<telerik:RadGridView.Columns>
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo1}" MinWidth="100" />
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo2}" MinWidth="100" />
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo3}" Width="*" />
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo4}" MinWidth="100" />
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo5}" MinWidth="100" />
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo6}" MinWidth="100" />
	</telerik:RadGridView.Columns>
</telerik:RadGridView>

<DataGrid ItemsSource="{Binding Foos}" AutoGenerateColumns="False" Grid.Row="1">
	<DataGrid.Columns>
		<DataGridTextColumn Binding="{Binding Foo1}" MinWidth="100" />
		<DataGridTextColumn Binding="{Binding Foo2}" MinWidth="100" />
		<DataGridTextColumn Binding="{Binding Foo3}" Width="*" />
		<DataGridTextColumn Binding="{Binding Foo4}" MinWidth="100" />
		<DataGridTextColumn Binding="{Binding Foo5}" MinWidth="100" />
		<DataGridTextColumn Binding="{Binding Foo6}" MinWidth="100" />
	</DataGrid.Columns>
</DataGrid>

in the native DataGrid after the Width of Foo4 column is increased towards Foo3, then the Width of Foo5/Foo6 columns can also be increased. We can implement similar behavior in the RadGridView as well. 

Currently, the GridViewMergedCell cannot be selected. Allow selecting the merged cells via the UI or code. 

At the moment RadGridView has only a CurrentMergedCell property.

Hello,

Regarding this forum question, it will be good if you add the attached property VisibleColumnsCount or IsAnyColumnVisible so I can hide the rows when there are 0 columns. Please read the following link for full information:

https://www.telerik.com/forums/radgridview---hide-rows-when-columns-are-not-visible

I have a license ok behalf my company

Currently, the range of the ScaleFactor property is between 0.1 and 4.0. We could include API to allow the user to set minimum and maximum boundaries that are between the default range (0.1 and 4.0).

For example:

• MinimumScaleFactor=0.8 
• MaximumScaleFactor = 1.5