Click element within Data Grid Column Header

Question

I have applied a custom style to my DataGrid's column headers. Here is a simplified version of it:

<Style x:Key="DataGridColumnHeaderStyle" TargetType="{x:Type DataGridColumnHeader}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="DataGridColumnHeader">
                <Grid>
                    <Border BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" HorizontalAlignment="{TemplateBinding HorizontalAlignment}" VerticalAlignment="{TemplateBinding VerticalAlignment}">
                        <Grid>
                            <StackPanel Orientation="Horizontal">
                                <ContentPresenter Margin="5 0 5 0" HorizontalAlignment="Center" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
                                <Image IsHitTestVisible="True" Source="pin.png">
                                    <Image.InputBindings>
                                        <MouseBinding MouseAction="LeftClick" Command="{x:Static myView:MyCommand}" CommandParameter="{Binding}" />
                                    </Image.InputBindings>
                                </Image>
                            </StackPanel>
                        </Grid>
                    </Border>
                    <Thumb x:Name="PART_LeftHeaderGripper" Style="{StaticResource DataGridColumnHeaderResizeThumb}"/>
                    <Thumb x:Name="PART_RightHeaderGripper" HorizontalAlignment="Right" Style="{StaticResource DataGridColumnHeaderResizeThumb}"/>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

I am struggling to get the command to fire when clicking the image. Is there something I am missing? Is there a different way that I can fire a command when clicking an element (i.e. an image) within the DataGridColumnHeader?

Some more details: MyCommand is defined in the Window's CommandBindings. I have not included this code here. I have other commands defined similarly for other elements (i.e. DataGridCell) that work OK. It seems there is something specific to the way the DataGridColumnHeader element that prevents the command to be fired.

Answer 1

It seems like you're binding to the type MyCommand under xmlns myView; instead, you should be binding to an instance of MyCommand (assuming class MyCommand implements ICommand). You may consider implementing singleton here. Or you could define a static instance of MyCommand anywhere.