Telerik UI for Silverlight

The RadChart exposes the LegendStyle property of type Style. It is applied to the ChartLegend control inside the RadChart. You can also style the Legend Items by setting an appropriate style to the LegendItemStyle of the ChartLegend control.

You have two options:

  • To create an empty styles and set it up on your own.
  • To copy the default styles of the control and modify it.

This topic will show you how to perform the second one.

Modifying the Default Styles

Note

The ChartLegend and the ChartLegendItem controls are located in the Telerik.Windows.Controls.Charting namespace of the Telerik.Windows.Controls.Charting assembly. In order to use them you have to declare it in XAML:

Colorized Example Code

 

xmlns:telerikCharting="clr-namespace:Telerik.Windows.Controls.Charting;assembly=Telerik.Windows.Controls.Charting"

XAMLLanguage Filtered SectionASP.NET

When working in Expression Blend, the namespaces that are needed will be added automatically.

Load your project in Expression Blend and open the User Control that holds the RadChart. You have to use a dummy controls in order to get the default styles. To create one find the ChartLegend or the ChartLegendItem control in the 'Assets' pane and draw one on the art board. In the 'Objects and Timeline' pane select the control, you've drawn and from the menu choose Object -> Edit Style -> Edit a Copy. You will be prompted for the name of the style and where to be placed.

Tip
If you choose to define the style in Application, it would be available for the entire application. This allows you to define a style only once and then reuse it where needed.

After clicking 'OK', Expression Blend will generate the default value for the selected Style in the Resources section of your User Control. The properties available for the style will be loaded in the 'Properties' pane and you will be able to modify their default values. You can also edit the generated XAML in the XAML View or in Visual Studio.

Tip
To change the fill of the legend item's marker set the MarkerFill property of the CHhrtLegendItem through its Style. For the stroke of the marker use the Stroke property of the ChartLegendItem.

If you go to the 'Resources' pane, you will see an editable list of resources generated together with the style and used by it. In this list you will find the brushes, styles and templates needed to change the visual appearance of the targeted control. Their names indicate to which part of the appearance they are assigned.

Here are the resources generated with the ChartLegendStyle:

 

  • LegendForeground - a brush, that represent the foreground color of the ChartLegend.
  • LegendBackground - a brush, that represents the background color of the ChartLegend.
  • LegendBorderBrush - a brush, that represents the border color of the ChartLegend.
  • LegendBorderThickness - represents the thickness of the border around the ChartLegend.
  • LegendItemMarkerShape - represents the shape of the marker inside the ChartLegend's item.
  • ChartLegendStyle - the Style, applied to the ChartLegend control.

Here are the resources generated with the ChartLegendItemStyle:

 

  • LegendForeground - a brush, that represents the foreground color of the ChartLegendItem.
  • LegendItemMarkerMask - a brush, that represents the background of the mask element for the ChatLegendItem's marker.
  • LegendItemMarkerMaskStroke - a brush, that represents the border color of the mask element for the ChatLegendItem's marker.
  • LegendItemMarkerMaskStrokeThickness - that represents the thickness of the border of the mask element for the ChatLegendItem's marker.
  • LegendItemMarkerMaskStroke - a brush, that represents the opacity mask of the mask element for the ChatLegendItem's marker.
  • LegendItemMarkerMask - a brush, that represents the background of the secondary mask element for the ChatLegendItem's marker.
  • ChartLegendItemStyle - the Style, applied to the ChartLegendItem control.

To apply the styles to the real controls, set the ChartLegendItemStyle in the Style for the ChartLegend.

CopyXAML
<Style x:Key="ChartLegendStyle"
       TargetType="telerikCharting:ChartLegend">
    ...
    <Setter Property="LegendItemStyle"
            Value="{StaticResource ChartLegendItemStyle}" />
    ...
</Style>

After that set the ChartLegendStyle to the RadChart.

CopyXAML
<telerikChart:RadChart x:Name="radChart"
                       LegendStyle="{StaticResource ChartLegendStyle}">
Note

Don't forget to delete the dummy controls, when you finish editing the style.

Here is the XAML, generated for the Styles:

CopyXAML
<LinearGradientBrush x:Key="LegendItemMarkerMask"
                        EndPoint="0.5,1"
                        StartPoint="0.5,0">
    <GradientStop Color="#D8FFFFFF"
                    Offset="0.009" />
    <GradientStop Color="#66FFFFFF"
                    Offset="1" />
    <GradientStop Color="Transparent"
                    Offset="0.43" />
    <GradientStop Color="#7FFFFFFF"
                    Offset="0.42" />
</LinearGradientBrush>
<SolidColorBrush x:Key="LegendItemMarkerMaskOpacityMask"
                    Color="#FF000000" />
<SolidColorBrush x:Key="LegendItemMarkerMaskStroke"
                    Color="White" />
<System:Double x:Key="LegendItemMarkerMaskStrokeThickness">1</System:Double>
<SolidColorBrush x:Key="LegendItemMarkerMask2"
                    Color="Transparent" />
<Style x:Key="ChartLegendItemStyle"
        TargetType="telerik:ChartLegendItem">
    <Setter Property="Foreground"
            Value="{StaticResource LegendForeground}" />
    <Setter Property="Padding"
            Value="5,0,5,0" />
    <Setter Property="Margin"
            Value="0,3,0,2" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="telerik:ChartLegendItem">
                <Grid x:Name="PART_MainContainer"
                        Background="{TemplateBinding Background}"
                        HorizontalAlignment="Stretch"
                        VerticalAlignment="Top">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto" />
                        <ColumnDefinition />
                    </Grid.ColumnDefinitions>
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="HoverStates">
                            <VisualState x:Name="Normal">
                                <Storyboard>
                                    <DoubleAnimation Duration="0.00:00:00.15"
                                                        To="1.0"
                                                        Storyboard.TargetProperty="Opacity"
                                                        Storyboard.TargetName="PART_MainContainer" />
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Hovered">
                                <Storyboard>
                                    <DoubleAnimation Duration="0.00:00:00.15"
                                                        To="1.0"
                                                        Storyboard.TargetProperty="Opacity"
                                                        Storyboard.TargetName="PART_MainContainer" />
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Hidden">
                                <Storyboard>
                                    <DoubleAnimation Duration="0.00:00:00.15"
                                                        To="0.15"
                                                        Storyboard.TargetProperty="Opacity"
                                                        Storyboard.TargetName="PART_MainContainer" />
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="SelectionStates">
                            <VisualState x:Name="Unselected" />
                            <VisualState x:Name="Selected">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Duration="0.00:00:00.05"
                                                                    Storyboard.TargetProperty="Stroke"
                                                                    Storyboard.TargetName="PART_LegendItemMarker">
                                        <DiscreteObjectKeyFrame KeyTime="0.00:00:00.0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <SolidColorBrush Color="#B2000000" />
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Duration="0.00:00:00.05"
                                                                    Storyboard.TargetProperty="StrokeThickness"
                                                                    Storyboard.TargetName="PART_LegendItemMarker">
                                        <DiscreteObjectKeyFrame KeyTime="0.00:00:00.0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <System:Double>2</System:Double>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Duration="0.00:00:00.05"
                                                                    Storyboard.TargetProperty="StrokeThickness"
                                                                    Storyboard.TargetName="PART_SelectedState">
                                        <DiscreteObjectKeyFrame KeyTime="0.00:00:00.0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <System:Double>0</System:Double>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <Path x:Name="PART_LegendItemMarker"
                            Height="16"
                            Margin="{TemplateBinding Margin}"
                            Style="{TemplateBinding ItemStyle}"
                            Stretch="Fill"
                            StrokeThickness="{TemplateBinding MarkerStrokeThickness}"
                            Width="16">
                            <Path.Data>
                                <PathGeometry x:Name="PART_ItemMarkerGeometry" />
                            </Path.Data>
                     </Path>
                    <Path x:Name="PART_SelectedState"
                            Fill="{StaticResource LegendItemMarkerMask}"
                            Height="14"
                            Margin="{TemplateBinding Margin}"
                            OpacityMask="{StaticResource LegendItemMarkerMaskOpacityMask}"
                            Stretch="Fill"
                            Stroke="{StaticResource LegendItemMarkerMaskStroke}"
                            StrokeThickness="{StaticResource LegendItemMarkerMaskStrokeThickness}"
                            Width="14">
                        <Path.Data>
                            <PathGeometry x:Name="PART_ItemMarkerMaskGeometry" />
                        </Path.Data>
                    </Path>
                    <Path Fill="{StaticResource LegendItemMarkerMask2}"
                            Height="14"
                            Margin="{TemplateBinding Margin}"
                            Stretch="Fill"
                            Width="14">
                      <Path.Data>
                        <PathGeometry x:Name="PART_ItemMarkerMaskGeometry2" />
                      </Path.Data>
                   </Path>
                    <TextBlock x:Name="PART_TextBlock"
                                Grid.Column="1"
                                Foreground="{TemplateBinding Foreground}"
                                Margin="{TemplateBinding Margin}"
                                Padding="{TemplateBinding Padding}"
                                Text="{TemplateBinding Label}" />
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>
<SolidColorBrush x:Key="LegendForeground"
                    Color="#FF000000" />
<LinearGradientBrush x:Key="LegendBackground"
                        EndPoint="1.96,0.5"
                        StartPoint="-0.96,0.5">
    <GradientStop Color="#FFB5B5B5" />
    <GradientStop Color="#FFF0F0F0"
                    Offset="0.5" />
</LinearGradientBrush>
<SolidColorBrush x:Key="LegendBorderBrush"
                    Color="#FF848484" />
<Thickness x:Key="LegendBorderThickness">1</Thickness>
<telerik:MarkerShape x:Key="LegendItemMarkerShape">SquareRounded</telerik:MarkerShape>
<telerik:TextToVisibilityConverter x:Key="textToVisibilityConverter" />
<Style x:Key="ChartLegendStyle"
        TargetType="telerik:ChartLegend">
    <Setter Property="Foreground"
            Value="{StaticResource LegendForeground}" />
    <Setter Property="Background"
            Value="{StaticResource LegendBackground}" />
    <Setter Property="Padding"
            Value="10,10,10,5" />
    <Setter Property="Margin"
            Value="0" />
    <Setter Property="BorderBrush"
            Value="{StaticResource LegendBorderBrush}" />
    <Setter Property="BorderThickness"
            Value="{StaticResource LegendBorderThickness}" />
    <Setter Property="HeaderFontWeight"
            Value="Bold" />
    <Setter Property="HorizontalContentAlignment"
            Value="Stretch" />
    <Setter Property="VerticalContentAlignment"
            Value="Stretch" />
    <Setter Property="LegendItemMarkerShape"
            Value="{StaticResource LegendItemMarkerShape}" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="telerik:ChartLegend">
                <Border BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}"
                        Background="{TemplateBinding Background}">
                    <Grid Margin="{TemplateBinding Padding}">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="Auto" />
                            <RowDefinition Height="*" />
                        </Grid.RowDefinitions>
                        <ContentControl ContentTemplate="{TemplateBinding HeaderTemplate}"
                                        Content="{TemplateBinding Header}"
                                        Foreground="{TemplateBinding Foreground}"
                                        FontWeight="{TemplateBinding HeaderFontWeight}" />
                        <ItemsPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                        Grid.Row="1"
                                        VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
                    </Grid>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
    <Setter Property="ItemsPanel">
        <Setter.Value>
            <ItemsPanelTemplate>
                <telerik:RadWrapPanel Orientation="{Binding ItemsPanelOrientation}" />
            </ItemsPanelTemplate>
        </Setter.Value>
    </Setter>
    <Setter Property="HeaderTemplate">
        <Setter.Value>
            <DataTemplate>
                <Grid>
                    <TextBlock FontSize="12"
                                HorizontalAlignment="Left"
                                Height="Auto"
                                Padding="0,0,0,2"
                                TextWrapping="Wrap"
                                Text="{Binding}"
                                Visibility="{Binding Converter={StaticResource textToVisibilityConverter}}"
                                Width="Auto" />
                </Grid>
            </DataTemplate>
        </Setter.Value>
    </Setter>
</Style>

See Also