Templated Nodes
The Telerik RadTreeView is a lookless and completely stylable control. This tutorial will demonstrate how you can build a horizontal treeview by simply using Styles and ControlTemplates.
Here is how the final result should look like:
For the purpose of this tutorial will be used the following treeview declaration:
<telerik:RadTreeView IsExpandOnSingleClickEnabled="True">
<telerik:RadTreeViewItem Header="THE FINAL">
<telerik:RadTreeViewItem Header="Lakers">
<telerik:RadTreeViewItem Header="Lakers">
<telerik:RadTreeViewItem Header="Lakers"/>
<telerik:RadTreeViewItem Header="4 : 2" IsEnabled="False"/>
<telerik:RadTreeViewItem Header="Utah"/>
</telerik:RadTreeViewItem>
<telerik:RadTreeViewItem Header="4 : 3" IsEnabled="False"/>
<telerik:RadTreeViewItem Header="SA Spurs">
<telerik:RadTreeViewItem Header="Hornets"/>
<telerik:RadTreeViewItem Header="3 : 4" IsEnabled="False"/>
<telerik:RadTreeViewItem Header="SA Spurs"/>
</telerik:RadTreeViewItem>
</telerik:RadTreeViewItem>
<telerik:RadTreeViewItem Header="Boston" Background="LightGreen">
<telerik:RadTreeViewItem Header="Boston">
<telerik:RadTreeViewItem Header="Boston"/>
<telerik:RadTreeViewItem Header="4 : 3" IsEnabled="False"/>
<telerik:RadTreeViewItem Header="Cleveland"/>
</telerik:RadTreeViewItem>
<telerik:RadTreeViewItem Header="4 : 3" IsEnabled="False"/>
<telerik:RadTreeViewItem Header="Detroit">
<telerik:RadTreeViewItem Header="Detroit"/>
<telerik:RadTreeViewItem Header="4 : 1" IsEnabled="False"/>
<telerik:RadTreeViewItem Header="Orlando"/>
</telerik:RadTreeViewItem>
</telerik:RadTreeViewItem>
</telerik:RadTreeViewItem>
</telerik:RadTreeView>
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The treeview has to be made horizontal. In order to do that you need to set the ItemContainerStyle property of the RadTreeView and RadTreeViewItem.
Declare the following style in the resources of your application. It will set the ItemsPanel to a StackPanel with Horizontal orientation:
<Style TargetType="telerik:RadTreeViewItem" x:Key="TreeViewItemStyle"> <Setter Property="IsExpanded" Value="True"></Setter> <Setter Property="ItemsPanel"> <Setter.Value> <ItemsPanelTemplate> <StackPanel HorizontalAlignment="Center" Margin="4,6" Orientation="Horizontal" /> </ItemsPanelTemplate> </Setter.Value> </Setter> </Style><Style TargetType="{x:Type telerik:RadTreeViewItem}" x:Key="TreeViewItemStyle"> <Setter Property="IsExpanded" Value="True"></Setter> <Setter Property="ItemsPanel"> <Setter.Value> <ItemsPanelTemplate> <StackPanel HorizontalAlignment="Center" Margin="4,6" Orientation="Horizontal" /> </ItemsPanelTemplate> </Setter.Value> </Setter> </Style>Apply this style to the ItemContainerStyle of the treeview and each treeview item.
<telerik:RadTreeView IsExpandOnSingleClickEnabled="True" ItemContainerStyle="{StaticResource TreeViewItemStyle}"> <telerik:RadTreeViewItem Header="THE FINAL" ItemContainerStyle="{StaticResource TreeViewItemStyle}"> <telerik:RadTreeViewItem Header="Lakers" ItemContainerStyle="{StaticResource TreeViewItemStyle}"> <telerik:RadTreeViewItem Header="Lakers" ItemContainerStyle="{StaticResource TreeViewItemStyle}"> <telerik:RadTreeViewItem Header="Lakers" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> <telerik:RadTreeViewItem Header="4 : 2" IsEnabled="False" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> <telerik:RadTreeViewItem Header="Utah" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> </telerik:RadTreeViewItem> <telerik:RadTreeViewItem Header="4 : 3" IsEnabled="False" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> <telerik:RadTreeViewItem Header="SA Spurs" ItemContainerStyle="{StaticResource TreeViewItemStyle}"> <telerik:RadTreeViewItem Header="Hornets" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> <telerik:RadTreeViewItem Header="3 : 4" IsEnabled="False" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> <telerik:RadTreeViewItem Header="SA Spurs" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> </telerik:RadTreeViewItem> </telerik:RadTreeViewItem> <telerik:RadTreeViewItem Header="Boston" Background="LightGreen" ItemContainerStyle="{StaticResource TreeViewItemStyle}"> <telerik:RadTreeViewItem Header="Boston" ItemContainerStyle="{StaticResource TreeViewItemStyle}"> <telerik:RadTreeViewItem Header="Boston" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> <telerik:RadTreeViewItem Header="4 : 3" IsEnabled="False" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> <telerik:RadTreeViewItem Header="Cleveland" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> </telerik:RadTreeViewItem> <telerik:RadTreeViewItem Header="4 : 3" IsEnabled="False" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> <telerik:RadTreeViewItem Header="Detroit" ItemContainerStyle="{StaticResource TreeViewItemStyle}"> <telerik:RadTreeViewItem Header="Detroit" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> <telerik:RadTreeViewItem Header="4 : 1" IsEnabled="False" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> <telerik:RadTreeViewItem Header="Orlando" ItemContainerStyle="{StaticResource TreeViewItemStyle}"/> </telerik:RadTreeViewItem> </telerik:RadTreeViewItem> </telerik:RadTreeViewItem> </telerik:RadTreeView>Additionally you need to set the ItemsPanel of the treeview:
<telerik:RadTreeView IsExpandOnSingleClickEnabled="True" ItemContainerStyle="{StaticResource TreeViewItemStyle}"> <telerik:RadTreeView.ItemsPanel> <ItemsPanelTemplate> <StackPanel VerticalAlignment="Top" Orientation="Horizontal" HorizontalAlignment="Center" /> </ItemsPanelTemplate> </telerik:RadTreeView.ItemsPanel> <telerik:RadTreeViewItem Header="THE FINAL" ItemContainerStyle="{StaticResource TreeViewItemStyle}"> ......................So far you should have the following result:
The next step is to make some visual enhancements in the tree.
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Style the expander. If you want to read more information about how to style a treeview expander, see the main topic Styling Expander.
Add the following style declaration in your resources and apply it on the ExpanderStyle property of the treeview:
<Style TargetType="ToggleButton" x:Key="ExpanderStyle"> <Setter Property="IsEnabled" Value="True" /> <Setter Property="IsTabStop" Value="False" /> <Setter Property="Cursor" Value="Hand" /> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="ToggleButton"> <Grid> <VisualStateManager.VisualStateGroups> <VisualStateGroup x:Name="CommonStates"> <VisualState x:Name="Normal"> </VisualState> </VisualStateGroup> <VisualStateGroup x:Name="CheckStates"> <VisualState x:Name="Checked"> <Storyboard> <DoubleAnimation Duration="0:0:0.2" Storyboard.TargetName="ExpandedStates" Storyboard.TargetProperty="Opacity" To="1" /> <DoubleAnimation Duration="0:0:0.2" Storyboard.TargetName="CollapsedStates" Storyboard.TargetProperty="Opacity" To="0" /> </Storyboard> </VisualState> <VisualState x:Name="Unchecked"> <Storyboard> <DoubleAnimation Duration="0:0:0.2" Storyboard.TargetName="ExpandedStates" Storyboard.TargetProperty="Opacity" To="0" /> <DoubleAnimation Duration="0:0:0.2" Storyboard.TargetName="CollapsedStates" Storyboard.TargetProperty="Opacity" To="1" /> </Storyboard> </VisualState> </VisualStateGroup> </VisualStateManager.VisualStateGroups> <Grid x:Name="CollapsedStates"> <Path x:Name="CollapsedVisual" Height="10" Width="5" Stretch="Fill" Stroke="#FF7C7C7C" Data="M1098.3334,527.90997 L1098.3334,536.30115 L1102.2695,532.36487 z" RenderTransformOrigin="0.5,0.5" /> </Grid> <Grid x:Name="ExpandedStates"> <Path x:Name="ExpandedVisual" Height="10" Width="5" Fill="#FF7C7C7C" Stretch="Fill" Stroke="#FF7C7C7C" Data="M1098.3334,527.90997 L1098.3334,536.30115 L1102.2695,532.36487 z" RenderTransformOrigin="0.5,0.5"> <Path.RenderTransform> <TransformGroup> <ScaleTransform ScaleX="1" ScaleY="1" /> <SkewTransform AngleX="0" AngleY="0" /> <RotateTransform Angle="90" /> <TranslateTransform X="0" Y="0" /> </TransformGroup> </Path.RenderTransform> </Path> </Grid> </Grid> </ControlTemplate> </Setter.Value> </Setter> </Style><Style TargetType="{x:Type ToggleButton}" x:Key="ExpanderStyle"> <Setter Property="IsEnabled" Value="True" /> <Setter Property="IsTabStop" Value="False" /> <Setter Property="Cursor" Value="Hand" /> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type ToggleButton}"> <Grid> <Grid x:Name="CollapsedStates"> <Path x:Name="CollapsedVisual" Height="10" Width="5" Stretch="Fill" Stroke="#FF7C7C7C" Data="M1098.3334,527.90997 L1098.3334,536.30115 L1102.2695,532.36487 z" RenderTransformOrigin="0.5,0.5" /> </Grid> <Grid x:Name="ExpandedStates"> <Path x:Name="ExpandedVisual" Height="10" Width="5" Fill="#FF7C7C7C" Stretch="Fill" Stroke="#FF7C7C7C" Data="M1098.3334,527.90997 L1098.3334,536.30115 L1102.2695,532.36487 z" RenderTransformOrigin="0.5,0.5"> <Path.RenderTransform> <TransformGroup> <ScaleTransform ScaleX="1" ScaleY="1" /> <SkewTransform AngleX="0" AngleY="0" /> <RotateTransform Angle="90" /> <TranslateTransform X="0" Y="0" /> </TransformGroup> </Path.RenderTransform> </Path> </Grid> </Grid> <ControlTemplate.Triggers> <Trigger Property="IsChecked" Value="True"> <Trigger.EnterActions> <BeginStoryboard> <Storyboard> <DoubleAnimation Duration="0:0:0.2" Storyboard.TargetName="ExpandedStates" Storyboard.TargetProperty="Opacity" To="1" /> <DoubleAnimation Duration="0:0:0.2" Storyboard.TargetName="CollapsedStates" Storyboard.TargetProperty="Opacity" To="0" /> </Storyboard> </BeginStoryboard> </Trigger.EnterActions> <Trigger.ExitActions> <BeginStoryboard> <Storyboard> <DoubleAnimation Duration="0:0:0.2" Storyboard.TargetName="ExpandedStates" Storyboard.TargetProperty="Opacity" To="0" /> <DoubleAnimation Duration="0:0:0.2" Storyboard.TargetName="CollapsedStates" Storyboard.TargetProperty="Opacity" To="1" /> </Storyboard> </BeginStoryboard> </Trigger.ExitActions> </Trigger> </ControlTemplate.Triggers> </ControlTemplate> </Setter.Value> </Setter> </Style><telerik:RadTreeView IsExpandOnSingleClickEnabled="True" ItemContainerStyle="{StaticResource TreeViewItemStyle}" ExpanderStyle="{StaticResource ExpanderStyle}">And the effect can be seen on the next snapshot:
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You need to create the template for the treeview nodes. Add the following ControlTemplate declaration to your application resources:
<ControlTemplate TargetType="telerik:RadTreeViewItem" x:Key="TreeViewItemDefaultTemplate"> <Grid Margin="2" Height="Auto" VerticalAlignment="Top"> <Grid.RowDefinitions> <RowDefinition Height="Auto" /> <RowDefinition Height="Auto" /> </Grid.RowDefinitions> <Grid Grid.Row="0" x:Name="HeaderRow" Height="Auto" VerticalAlignment="Bottom"> <Rectangle RadiusX="3" RadiusY="3" Stroke="#FF709FDA" StrokeLineJoin="Bevel" StrokeThickness="1"> <Rectangle.Fill> <LinearGradientBrush EndPoint="0.5,0.034" StartPoint="0.5,0.966"> <GradientStop Color="#FFE4E5F0" Offset="0" /> <GradientStop Color="#FFFFFFFF" Offset="1" /> </LinearGradientBrush> </Rectangle.Fill> </Rectangle> <Border x:Name="SelectionVisual" Visibility="Collapsed" BorderBrush="#FFA8C9D8" BorderThickness="1,1,1,1" CornerRadius="3,3,3,3"> <Border.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="#FF00CCFF" Offset="0" /> <GradientStop Color="#FF9BB1FF" Offset="1" /> </LinearGradientBrush> </Border.Background> <Border CornerRadius="2,2,2,2" BorderBrush="#FFFFFFFF" BorderThickness="2"> <Border.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="#E5FFFFFF" Offset="0" /> <GradientStop Color="#33FFFFFF" Offset="1" /> <GradientStop Color="#4DFFFFFF" Offset="0.5" /> <GradientStop Color="#00FFFFFF" Offset="0.511" /> </LinearGradientBrush> </Border.Background> </Border> </Border> <StackPanel> <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="5"> <Image MaxWidth="25" MaxHeight="25" Stretch="Fill" x:Name="Image" Source="{TemplateBinding DefaultImageSrc}" Margin="2" /> <ContentControl Name="Header" Padding="5" Content="{TemplateBinding Header}" ContentTemplate="{TemplateBinding HeaderTemplate}" HorizontalAlignment="Center" VerticalAlignment="Center" /> </StackPanel> <ToggleButton x:Name="Expander" Margin="0,0,0,5"></ToggleButton> </StackPanel> <Rectangle x:Name="FocusVisual" RadiusX="3" RadiusY="3" Visibility="Collapsed" Stroke="Black" StrokeThickness="0.75" StrokeDashArray="1,2" IsHitTestVisible="False" /> </Grid> <ItemsPresenter Grid.Row="1" x:Name="ItemsHost" Visibility="Collapsed" /> </Grid> </ControlTemplate><ControlTemplate TargetType="{x:Type telerik:RadTreeViewItem}" x:Key="TreeViewItemDefaultTemplate"> <Grid Margin="2" Height="Auto" VerticalAlignment="Top"> <Grid.RowDefinitions> <RowDefinition Height="Auto" /> <RowDefinition Height="Auto" /> </Grid.RowDefinitions> <Grid Grid.Row="0" x:Name="HeaderRow" Height="Auto" VerticalAlignment="Bottom"> <Rectangle RadiusX="3" RadiusY="3" Stroke="#FF709FDA" StrokeLineJoin="Bevel" StrokeThickness="1"> <Rectangle.Fill> <LinearGradientBrush EndPoint="0.5,0.034" StartPoint="0.5,0.966"> <GradientStop Color="#FFE4E5F0" Offset="0" /> <GradientStop Color="#FFFFFFFF" Offset="1" /> </LinearGradientBrush> </Rectangle.Fill> </Rectangle> <Border x:Name="SelectionVisual" Visibility="Collapsed" BorderBrush="#FFA8C9D8" BorderThickness="1,1,1,1" CornerRadius="3,3,3,3"> <Border.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="#FF00CCFF" Offset="0" /> <GradientStop Color="#FF9BB1FF" Offset="1" /> </LinearGradientBrush> </Border.Background> <Border CornerRadius="2,2,2,2" BorderBrush="#FFFFFFFF" BorderThickness="2"> <Border.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="#E5FFFFFF" Offset="0" /> <GradientStop Color="#33FFFFFF" Offset="1" /> <GradientStop Color="#4DFFFFFF" Offset="0.5" /> <GradientStop Color="#00FFFFFF" Offset="0.511" /> </LinearGradientBrush> </Border.Background> </Border> </Border> <StackPanel> <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="5"> <Image MaxWidth="25" MaxHeight="25" Stretch="Fill" x:Name="Image" Source="{TemplateBinding DefaultImageSrc}" Margin="2" /> <ContentControl Name="Header" Padding="5" Content="{TemplateBinding Header}" ContentTemplate="{TemplateBinding HeaderTemplate}" HorizontalAlignment="Center" VerticalAlignment="Center" /> </StackPanel> <ToggleButton x:Name="Expander" Margin="0,0,0,5"></ToggleButton> </StackPanel> <Rectangle x:Name="FocusVisual" RadiusX="3" RadiusY="3" Visibility="Collapsed" Stroke="Black" StrokeThickness="0.75" StrokeDashArray="1,2" IsHitTestVisible="False" /> </Grid> <ItemsPresenter Grid.Row="1" x:Name="ItemsHost" Visibility="Collapsed" /> </Grid> </ControlTemplate> -
In your TreeViewItemStyle set the Template property to the ControlTemplate declared on the previous step:
<Style TargetType="telerik:RadTreeViewItem" x:Key="TreeViewItemStyle"> <Setter Property="Template" Value="{StaticResource TreeViewItemDefaultTemplate}" /> <Setter Property="IsExpanded" Value="True"></Setter> <Setter Property="ItemsPanel"> <Setter.Value> <ItemsPanelTemplate> <StackPanel HorizontalAlignment="Center" Margin="4,6" Orientation="Horizontal" /> </ItemsPanelTemplate> </Setter.Value> </Setter> </Style><Style TargetType="{x:Type telerik:RadTreeViewItem}" x:Key="TreeViewItemStyle"> <Setter Property="Template" Value="{StaticResource TreeViewItemDefaultTemplate}" /> <Setter Property="IsExpanded" Value="True"></Setter> <Setter Property="ItemsPanel"> <Setter.Value> <ItemsPanelTemplate> <StackPanel HorizontalAlignment="Center" Margin="4,6" Orientation="Horizontal" /> </ItemsPanelTemplate> </Setter.Value> </Setter> </Style>We are one step closer to the desired result:
In order to add animation to your treeview you need to use triggers.
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Selected
- Set the SelectionVisual's Visibility to Visible
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Focused
- Set the FocusVisual's Visibility to Visible
<ControlTemplate TargetType="telerik:RadTreeViewItem"
x:Key="TreeViewItemDefaultTemplate">
<Grid Margin="2" Height="Auto" VerticalAlignment="Top">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal">
<Storyboard>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="SelectionStates">
<VisualState x:Name="Unselected">
</VisualState>
<VisualState x:Name="Selected">
<Storyboard>
<ObjectAnimationUsingKeyFrames
Storyboard.TargetName="SelectionVisual"
Storyboard.TargetProperty="Visibility" Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualState x:Name="Focused">
<Storyboard>
<ObjectAnimationUsingKeyFrames
Storyboard.TargetName="FocusVisual"
Storyboard.TargetProperty="Visibility" Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Unfocused">
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="ExpandStates">
<VisualState x:Name="Expanded">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ItemsHost"
Storyboard.TargetProperty="Visibility" Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<DoubleAnimation Storyboard.TargetName="ItemsHost"
Storyboard.TargetProperty="Opacity" From="0.1" To="1.0"
Duration="0:0:0.2" />
</Storyboard>
</VisualState>
<VisualState x:Name="Collapsed">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="ItemsHost"
Storyboard.TargetProperty="Opacity" From="1" To="0.1"
Duration="0:0:0.2" />
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ItemsHost"
Storyboard.TargetProperty="Visibility" Duration="0"
BeginTime="0:0:0.2">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Grid Grid.Row="0" x:Name="HeaderRow" Height="Auto" VerticalAlignment="Bottom">
<Rectangle RadiusX="3" RadiusY="3" Stroke="#FF709FDA" StrokeLineJoin="Bevel"
StrokeThickness="1">
<Rectangle.Fill>
<LinearGradientBrush EndPoint="0.5,0.034" StartPoint="0.5,0.966">
<GradientStop Color="#FFE4E5F0" Offset="0" />
<GradientStop Color="#FFFFFFFF" Offset="1" />
</LinearGradientBrush>
</Rectangle.Fill>
</Rectangle>
<Border x:Name="SelectionVisual" Visibility="Collapsed"
BorderBrush="#FFA8C9D8" BorderThickness="1,1,1,1"
CornerRadius="3,3,3,3">
<Border.Background>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="#FF00CCFF" Offset="0" />
<GradientStop Color="#FF9BB1FF" Offset="1" />
</LinearGradientBrush>
</Border.Background>
<Border CornerRadius="2,2,2,2" BorderBrush="#FFFFFFFF"
BorderThickness="2">
<Border.Background>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="#E5FFFFFF" Offset="0" />
<GradientStop Color="#33FFFFFF" Offset="1" />
<GradientStop Color="#4DFFFFFF" Offset="0.5" />
<GradientStop Color="#00FFFFFF" Offset="0.511" />
</LinearGradientBrush>
</Border.Background>
</Border>
</Border>
<StackPanel>
<StackPanel Orientation="Horizontal" HorizontalAlignment="Center"
Margin="5">
<Image MaxWidth="25" MaxHeight="25" Stretch="Fill" x:Name="Image"
Source="{TemplateBinding DefaultImageSrc}" Margin="2" />
<ContentControl Name="Header" Padding="5"
Content="{TemplateBinding Header}"
ContentTemplate="{TemplateBinding HeaderTemplate}"
HorizontalAlignment="Center" VerticalAlignment="Center" />
</StackPanel>
<ToggleButton x:Name="Expander" Margin="0,0,0,5"></ToggleButton>
</StackPanel>
<Rectangle x:Name="FocusVisual" RadiusX="3" RadiusY="3"
Visibility="Collapsed" Stroke="Black" StrokeThickness="0.75"
StrokeDashArray="1,2" IsHitTestVisible="False" />
</Grid>
<ItemsPresenter Grid.Row="1" x:Name="ItemsHost" Visibility="Collapsed" />
</Grid>
</ControlTemplate>
Add three triggers to your control template, which are activated when the treeview item is selected, focused and expanded.
- When the IsSelected property is True, set the SelectionVisual's visibility to Visible. Accordingly, when the IsSelected property is False, set the SelectionVisual's visibility to Hidden.
- When the IsFocused property is True, set the FocusVisual's visibility to Visible. Accordingly, when the IsFocused property is False, set the FocusVisual's visibility to Hidden.
- When the IsExpanded property is True, set the ItemHost's visibility to Visible. Accordingly, when the IsExpanded property is False, set the ItemHost's visibility to Hidden.
Here is the complete XAML for ControlTemplate.Triggers section and the final result:
<ControlTemplate.Triggers>
<Trigger Property="IsSelected" Value="True">
<Trigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<ObjectAnimationUsingKeyFrames
Storyboard.TargetName="SelectionVisual"
Storyboard.TargetProperty="Visibility" Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</Trigger.EnterActions>
<Trigger.ExitActions>
<BeginStoryboard>
<Storyboard>
<ObjectAnimationUsingKeyFrames
Storyboard.TargetName="SelectionVisual"
Storyboard.TargetProperty="Visibility" Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Hidden</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</Trigger.ExitActions>
</Trigger>
<Trigger Property="IsFocused" Value="True">
<Trigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<ObjectAnimationUsingKeyFrames
Storyboard.TargetName="FocusVisual"
Storyboard.TargetProperty="Visibility" Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</Trigger.EnterActions>
<Trigger.ExitActions>
<BeginStoryboard>
<Storyboard>
<ObjectAnimationUsingKeyFrames
Storyboard.TargetName="FocusVisual"
Storyboard.TargetProperty="Visibility" Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Hidden</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</Trigger.ExitActions>
</Trigger>
<Trigger Property="IsExpanded" Value="True">
<Trigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ItemsHost"
Storyboard.TargetProperty="Visibility" Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<DoubleAnimation Storyboard.TargetName="ItemsHost"
Storyboard.TargetProperty="Opacity" From="0.1" To="1.0"
Duration="0:0:0.2" />
</Storyboard>
</BeginStoryboard>
</Trigger.EnterActions>
<Trigger.ExitActions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="ItemsHost"
Storyboard.TargetProperty="Opacity" From="1" To="0.1"
Duration="0:0:0.2" />
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ItemsHost"
Storyboard.TargetProperty="Visibility" Duration="0"
BeginTime="0:0:0.2">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</Trigger.ExitActions>
</Trigger>
</ControlTemplate.Triggers>
And here is the final result:
