Silverlight CheckBox - silverlight

Question

I want to change the background color of checkbox when its checked instead of show an icon but i have no idea of how to do this. I've tried to create a new "Rectangle" with a different background color and call him on VisualState "Checked" but it didnt work.
My code :
<Style TargetType="CheckBox">
<Setter Property="Background" Value="{StaticResource CheckBoxBackgroundBrush}" />
<Setter Property="BorderBrush" Value="{StaticResource CheckBoxBorderBrush}" />
<Setter Property="Foreground" Value="{StaticResource NormalFontBrush}" />
<Setter Property="HorizontalContentAlignment" Value="Left" />
<Setter Property="Padding" Value="6,1,0,0" />
<Setter Property="VerticalContentAlignment" Value="Center" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="CheckBox">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="13" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal" />
<VisualState x:Name="MouseOver">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)" Storyboard.TargetName="MouseOverBorder">
<DiscreteObjectKeyFrame KeyTime="0" Value="Visible" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)" Storyboard.TargetName="PressedBorder">
<DiscreteObjectKeyFrame KeyTime="0" Value="Visible" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation Duration="0" To=".55" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="contentPresenter" />
<DoubleAnimation Duration="0" To="0.55" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="DisabledVisualElement" />
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="CheckStates">
<VisualState x:Name="Checked">
<Storyboard>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="CheckIcon" />
</Storyboard>
</VisualState>
<VisualState x:Name="Unchecked" />
<VisualState x:Name="Indeterminate">
<Storyboard>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="IndeterminateIcon" />
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualState x:Name="Focused">
<Storyboard>
<DoubleAnimation Duration="0" Storyboard.TargetName="FocusVisualElement" Storyboard.TargetProperty="(FrameworkElement.Opacity)" To="1" />
</Storyboard>
</VisualState>
<VisualState x:Name="Unfocused" />
</VisualStateGroup>
<VisualStateGroup x:Name="ValidationStates">
<VisualState x:Name="Valid" />
<VisualState x:Name="InvalidUnfocused">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ValidationErrorElement">
<DiscreteObjectKeyFrame KeyTime="0" Value="Visible" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="InvalidFocused">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ValidationErrorElement">
<DiscreteObjectKeyFrame KeyTime="0" Value="Visible" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="IsOpen" Storyboard.TargetName="validationTooltip">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<System:Boolean>True</System:Boolean>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid Height="12" HorizontalAlignment="Left" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" Width="12">
<Rectangle x:Name="Background" Fill="{TemplateBinding Background}" Height="12" Stroke="{TemplateBinding BorderBrush}" Width="12" />
<Border x:Name="OuterHighlight" BorderBrush="{StaticResource ControlOuterHighlightBrush}" BorderThickness="0,0,1,1" CornerRadius="1,0,1,0" Margin="1,1,-1,-1" />
<Border x:Name="InnerShadow" BorderBrush="{StaticResource CheckBoxInnerShadowBrush}" BorderThickness="1,1,0,0" CornerRadius="0.5" Margin="1,1,0,0" />
<Border x:Name="MouseOverBorder" BorderBrush="{StaticResource ColorAccentBrush}" BorderThickness="1" Margin="1" Visibility="Collapsed" />
<Border x:Name="PressedBorder" BorderBrush="{StaticResource ColorAccentSubduedBrush}" BorderThickness="1" Margin="1" Visibility="Collapsed" />
<Path x:Name="CheckIcon" Data="M0.5625,5.0625 L1.5,3.9375 L2.9575791,4.9549685 C2.9575791,4.9549685 5.75,1.125 5.75,1.125 C5.75,1.125 6.9375,2 6.9375,2 C6.9375,2 3.186887,7.0000076 3.186887,7.0000076 z" Fill="{StaticResource CheckBoxColorAccentHighlightBrush}" FlowDirection="LeftToRight" Margin="2,2,0,1" Opacity="0"/>
<Rectangle x:Name="IndeterminateIcon" Fill="{StaticResource ColorAccentHighlightBrush}" Height="2" Opacity="0" Width="6" />
<Rectangle x:Name="DisabledVisualElement" Fill="{StaticResource DisabledBrush}" Height="12" Opacity="0" Width="12" />
<Rectangle x:Name="FocusVisualElement" IsHitTestVisible="False" Margin="2" Opacity="0" Stroke="{StaticResource FocusVisualBrush}" StrokeThickness="{StaticResource FocusVisualStrokeThickness}" />
<Border x:Name="ValidationErrorElement" BorderBrush="{StaticResource ErrorBrush}" BorderThickness="1" Margin="1" ToolTipService.PlacementTarget="{Binding RelativeSource={RelativeSource TemplatedParent}}" Visibility="Collapsed">
<ToolTipService.ToolTip>
<ToolTip x:Name="validationTooltip" DataContext="{Binding RelativeSource={RelativeSource TemplatedParent}}" Placement="Right" PlacementTarget="{Binding RelativeSource={RelativeSource TemplatedParent}}" Template="{StaticResource ValidationToolTipTemplate}">
<ToolTip.Triggers>
<EventTrigger RoutedEvent="Canvas.Loaded">
<BeginStoryboard>
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="IsHitTestVisible" Storyboard.TargetName="validationTooltip">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<System:Boolean>true</System:Boolean>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</ToolTip.Triggers>
</ToolTip>
</ToolTipService.ToolTip>
<Grid Background="Transparent" HorizontalAlignment="Right" Height="10" Margin="0,-4,-4,0" VerticalAlignment="Top" Width="10">
<Path Data="M 1,0 L5,0 A 2,2 90 0 1 7,2 L7,6 z" Fill="{StaticResource ErrorBrush}" Margin="0,3,0,0" />
</Grid>
</Border>
</Grid>
<ContentPresenter x:Name="contentPresenter" Content="{TemplateBinding Content}" ContentTemplate="{TemplateBinding ContentTemplate}" Grid.Column="1" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Thanks!

Answer 1

You are on the right track. Create a rectangle (or border) with the desired background color and Opacity 0. In the Checked state, animate the Opacity to 1. Alternatively, set the Visibility to Collapsed and animate visibility similar to how the PressedBorder element is animated in the Pressed state.
Under PressedBorder
<Border x:Name="CheckedBorder" BorderThickness="1" Margin="1" Background="Green" Visibility="Collapsed" />
In VSM:
<VisualState x:Name="Pressed">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)" Storyboard.TargetName="PressedBorder">
<DiscreteObjectKeyFrame KeyTime="0" Value="Visible" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>