Using the accordian control in Silverlight Toolkit With the Caliburn framework

I am trying to setup an accordion in the using Silverlight and and the Caliburn framework.

The issue is that the content pane does not show when I select an accordion Item.

my binding

<toolkit:Accordion.ItemTemplate>
                <DataTemplate>
                    <StackPanel>
                        <TextBlock Name="Title" Text="{Binding Title}" ></TextBlock>
                    </StackPanel>
         开发者_JS百科       </DataTemplate>

               </toolkit:Accordion.ItemTemplate>
              <toolkit:Accordion.ContentTemplate >
                <DataTemplate>
                    <ContentPresenter Content="{Binding SelectedActionStep}" />
                </DataTemplate>
            </toolkit:Accordion.ContentTemplate>

Try this:

xmlns:cal="http://www.caliburnproject.org"
...
<DataTemplate>
    <ContentControl cal:View.Model="{Binding SelectedActionStep}" />
</DataTemplate>