when use the RadTransitionControl's SlideAndZoomTransition effect for the RadTabControl, the radComboBox Multiple Selection will lost in the tabItem。
the radComboBox data is from the mvvm binding,after change the tabitem,the Multiple Selection become single selection.
the RadTabControl's style is following:
...
<ControlTemplate x:Key="TabControlTemplate" TargetType="telerik:RadTabControl">
<Grid>
<telerik:RadDockPanel LastChildFill="True">
<telerik:LayoutTransformControl x:Name="HeaderDockedElement" telerik:RadDockPanel.Dock="Top">
<Grid SnapsToDevicePixels="True">
<Border x:Name="HeaderBackground" Background="{TemplateBinding HeaderBackground}" Visibility="{TemplateBinding BackgroundVisibility}"/>
<telerik:RadDockPanel Panel.ZIndex="10">
<telerik:LayoutTransformControl x:Name="AdditionalContentTransform" Margin="0" telerik1:RadDockPanel.Dock="Right">
<ContentPresenter x:Name="AdditionalContentElement" Content="{TemplateBinding AdditionalContent}"/>
</telerik:LayoutTransformControl>
<ToggleButton x:Name="DropDownButtonElement"
Visibility="Collapsed"
telerik:RadDockPanel.Dock="Right"
Style="{TemplateBinding DropDownButtonStyle}"
ClickMode="Press"
IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}">
<telerik:RadContextMenu.ContextMenu>
<telerikTabControl:DropDownMenu x:Name="DropDownMenuElement"
StaysOpen="False"
Placement="Bottom"
Style="{TemplateBinding DropDownStyle}"
ItemTemplate="{TemplateBinding ItemDropDownContentTemplate}"
ItemTemplateSelector="{TemplateBinding ItemDropDownContentTemplateSelector}"
DisplayMemberPath="{TemplateBinding DropDownDisplayMemberPath}"/>
</telerik:RadContextMenu.ContextMenu>
</ToggleButton>
<RepeatButton x:Name="LeftScrollButtonElement" Style="{StaticResource ScrollButtonStyle}">
<telerik:RadGlyph Glyph="{StaticResource GlyphArrowChevronLeft}"/>
</RepeatButton>
<RepeatButton x:Name="RightScrollButtonElement" Style="{StaticResource ScrollButtonStyle}" telerik:RadDockPanel.Dock="Right">
<telerik:RadGlyph Glyph="{StaticResource GlyphArrowChevronRight}"/>
</RepeatButton>
<ScrollViewer x:Name="ScrollViewerElement"
Style="{StaticResource EmptyScrollViewerStyle}"
VerticalScrollBarVisibility="Disabled"
BorderThickness="0"
IsTabStop="False"
HorizontalScrollBarVisibility="{Binding (ScrollViewer.HorizontalScrollBarVisibility), RelativeSource={RelativeSource TemplatedParent}}">
<ItemsPresenter/>
</ScrollViewer>
</telerik:RadDockPanel>
</Grid>
</telerik:LayoutTransformControl>
<Border x:Name="ContentBorder"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=BorderThickness, Mode=TwoWay}"
Background="{TemplateBinding Background}"
Padding="{TemplateBinding Padding}">
<Grid>
<telerik:RadTransitionControl x:Name="ContentElement"
Visibility="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=IsContentPreserved,Converter={StaticResource InvertedBooleanToVisibilityConverter}}"
Content="{TemplateBinding SelectedContent}"
ContentTemplate="{TemplateBinding SelectedContentTemplate}"
ContentTemplateSelector="{TemplateBinding SelectedContentTemplateSelector}"
Duration="00:00:00.350">
<telerik:RadTransitionControl.Transition>
<local:TransitionSetFP>
<local:TransitionSetFP.BackTransition>
<telerik:SlideAndZoomTransition SlideDirection="LeftToRight" MinZoom="1" StartSlideAt="0.01" MinAlpha="1"/>
</local:TransitionSetFP.BackTransition>
<local:TransitionSetFP.ForwardTransition>
<telerik:SlideAndZoomTransition SlideDirection="RightToLeft" MinZoom="1" StartSlideAt="0.01" MinAlpha="1"/>
</local:TransitionSetFP.ForwardTransition>
</local:TransitionSetFP>
</telerik:RadTransitionControl.Transition>
</telerik:RadTransitionControl>
<Grid x:Name="ContentElementsPanel" Visibility="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=IsContentPreserved, Converter={StaticResource BooleanToVisibilityConverter}}"/>
</Grid>
</Border>
</telerik:RadDockPanel>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="DropDownDisplayMode" Value="Visible">
<Setter Property="Visibility" Value="Visible" TargetName="DropDownButtonElement"/>
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="DropDownDisplayMode" Value="WhenNeeded"/>
<Condition SourceName="ScrollViewerElement" Property="ComputedHorizontalScrollBarVisibility" Value="Visible"/>
</MultiTrigger.Conditions>
<Setter Property="Visibility" Value="Visible" TargetName="DropDownButtonElement"/>
</MultiTrigger>
<Trigger Property="TabStripPlacement" Value="Top">
<Setter Property="BorderThickness" TargetName="ContentBorder" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=BorderThickness, Converter={StaticResource ThicknessToOrientedThicknessConverter}, ConverterParameter=LeftBottomRight}"/>
</Trigger>
<Trigger Property="TabStripPlacement" Value="Left">
<Setter TargetName="DropDownMenuElement" Property="HorizontalOffset" Value="0"/>
<Setter TargetName="DropDownMenuElement" Property="VerticalOffset" Value="-3"/>
<Setter Property="telerik:RadDockPanel.Dock" Value="Left" TargetName="HeaderDockedElement"/>
<Setter Property="telerik:RadDockPanel.Dock" Value="Left" TargetName="AdditionalContentTransform"/>
<Setter Property="telerik:RadDockPanel.Dock" Value="Left" TargetName="DropDownButtonElement"/>
<Setter Property="LayoutTransform" TargetName="HeaderDockedElement">
<Setter.Value>
<RotateTransform Angle="-90"/>
</Setter.Value>
</Setter>
<Setter Property="BorderThickness" TargetName="ContentBorder" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=BorderThickness, Converter={StaticResource ThicknessToOrientedThicknessConverter}, ConverterParameter=TopRightBottom}"/>
</Trigger>
<Trigger Property="TabStripPlacement" Value="Right">
<Setter TargetName="DropDownMenuElement" Property="HorizontalOffset" Value="0"/>
<Setter TargetName="DropDownMenuElement" Property="VerticalOffset" Value="3"/>
<Setter Property="LayoutTransform" TargetName="HeaderDockedElement">
<Setter.Value>
<RotateTransform Angle="90"/>
</Setter.Value>
</Setter>
<Setter Property="BorderThickness" TargetName="ContentBorder" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=BorderThickness, Converter={StaticResource ThicknessToOrientedThicknessConverter}, ConverterParameter=TopLeftBottom}"/>
</Trigger>
<Trigger Property="TabStripPlacement" Value="Bottom">
<Setter TargetName="DropDownMenuElement" Property="HorizontalOffset" Value="3"/>
<Setter Property="telerik:RadDockPanel.Dock" Value="Left" TargetName="AdditionalContentTransform"/>
<Setter Property="telerik:RadDockPanel.Dock" Value="Left" TargetName="DropDownButtonElement"/>
<Setter Property="LayoutTransform" TargetName="HeaderDockedElement">
<Setter.Value>
<RotateTransform Angle="180"/>
</Setter.Value>
</Setter>
<Setter Property="LayoutTransform" TargetName="AdditionalContentTransform">
<Setter.Value>
<RotateTransform Angle="180"/>
</Setter.Value>
</Setter>
<Setter Property="BorderThickness" TargetName="ContentBorder" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=BorderThickness, Converter={StaticResource ThicknessToOrientedThicknessConverter}, ConverterParameter=TopRightLeft}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<Style TargetType="telerik:RadTabControl">
<Setter Property="mat:MaterialAssist.ShadowDepth" Value="Depth1"/>
<Setter Property="TextOptions.TextRenderingMode" Value="ClearType"/>
<Setter Property="BorderBrush" Value="{telerik1:FluentResource ResourceKey=BasicBrush}"/>
<Setter Property="HeaderBackground" Value="{telerik1:FluentResource ResourceKey=MainBrush}"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Background" Value="{telerik1:FluentResource ResourceKey=PrimaryBackgroundBrush}"/>
<Setter Property="MinWidth" Value="5"/>
<Setter Property="MinHeight" Value="20"/>
<Setter Property="HorizontalContentAlignment" Value="Stretch"/>
<Setter Property="VerticalContentAlignment" Value="Stretch"/>
<Setter Property="IsTabStop" Value="False"/>
<Setter Property="FontFamily" Value="{telerik1:FluentResource ResourceKey=FontFamily}"/>
<Setter Property="FontSize" Value="{telerik1:FluentResource ResourceKey=FontSize}"/>
<Setter Property="Foreground" Value="{telerik1:FluentResource ResourceKey=MarkerBrush}"/>
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<Primitives:TabWrapPanel/>
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
<Setter Property="DropDownButtonStyle" Value="{StaticResource DropDownButtonStyle}"/>
<Setter Property="DropDownStyle" Value="{StaticResource DropDownMenuStyle}"/>
<Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
<Setter Property="Template" Value="{StaticResource TabControlTemplate}"/>
</Style>