Question

I’ve edited a template from a checkbox, then I added an image into it without defining its “Source” property.

Style :

<Style x:Key="ImageCheckbox" TargetType="{x:Type CheckBox}">
        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
        <Setter Property="Background" Value="{StaticResource CheckBoxFillNormal}"/>
        <Setter Property="BorderBrush" Value="{StaticResource CheckBoxStroke}"/>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="FocusVisualStyle" Value="{StaticResource EmptyCheckBoxFocusVisual}"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type CheckBox}">
                    <Image x:Name="image" Width="20" Height="20" Stretch="UniformToFill"/>                      
                    <ControlTemplate.Triggers>
                        <Trigger Property="HasContent" Value="true">
                            <Setter Property="FocusVisualStyle" Value="{StaticResource CheckRadioFocusVisual}"/>
                            <Setter Property="Padding" Value="4,0,0,0"/>
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>       

My question is how to pass that “Source” property (in XAML) to “ImageCheckBox” template in this code :

<CheckBox Content="" Margin="0,2,0,0" Name="btTogglePalette" Grid.Row="1" Command="Helpers:UICommands.TogglePalette" 
                              IsChecked="{Binding Path=PaletteStatus, Mode=TwoWay}" VerticalAlignment="Center" HorizontalAlignment="Center" 
                              Style="{DynamicResource ImageCheckbox}">

So that the image will show the passed parameter.

Thank you

Answer 1

There is no way to pass custom parameters to a style or template. You can only access properties on the control or bound data. That said, you may be able to abuse the checkbox’s Tag property to accomplish this but I’m not 100% it will work.

The proper way to do it is to create a new custom control that derives from Checkbox and add a dependency property holding your image (of type ImageSource). That way, from your control template inside generic.xaml you can do

<!-- in generic.xaml, inside the ControlTemplate for your ImageCheckbox style -->
<Image Source="{TemplateBinding ImageSource}" />

and where you instantiate your checkbox you do

<local:ImageCheckbox ImageSource="Resources/MyImage.png" ...etc... />