How to set TabItem CommandBindings when using ItemsSource

Question

I have some workspaces presented inside a TabControl . Each workpace has some command bindings bound to some ApplicationCommands like

• New (Foo)
• Save (Bar)
• Close (Foo,Bar)

The menu is build by using these ApplicationCommands

<Menu>
    <MenuItem Command="ApplicationCommands.New"/>
    <MenuItem Command="ApplicationCommands.Save"/>
    <MenuItem Command="ApplicationCommands.Close"/>
</Menu>

It is very easy to use this commands when the TabControl is wired manually

<TabControl>
    <TabControl.Resources>
        <Style TargetType="TabItem">
            <Setter Property="HeaderTemplate" Value="{StaticResource ClosableTabItemTemplate}"/>
        </Style>
    </TabControl.Resources>
    <TabItem DataContext="{Binding Foo}" 
             Header="{Binding}" 
             Content="{Binding}" 
             local:AttachedProperties.RegisterCommandBindings="{Binding Path=CommandBindings}"/>
    <TabItem DataContext="{Binding Bar}" 
             Header="{Binding}" 
             Content="{Binding}" 
             local:AttachedProperties.RegisterCommandBindings="{Binding Path=CommandBindings}"/>
</TabControl>

When I select just the TabItem I can use the menu to execute the commands.

But the workspaces are not static, so I had to bind to a colletion of workspaces. Now it is not enough to select the TabItem , I also had to activate the content, to use the commands from the menu (not suprising, because the TabItem is active without any command binding)

<TabControl ItemsSource="{Binding Path=Workspaces}">
    <TabControl.Resources>
        <Style TargetType="TabItem">
            <Setter Property="HeaderTemplate" Value="{StaticResource ClosableTabItemTemplate}"/>
        </Style>
    </TabControl.Resources>
</TabControl>

Here the DataTemplate for the TabItem

<DataTemplate x:Key="ClosableTabItemTemplate">
    <DockPanel LastChildFill="True">
        <Button Content="X" DockPanel.Dock="Right" Command="{Binding Path=CloseCommand}"/>
        <TextBlock Text="{Binding Path=DisplayName}"/>
    </DockPanel>
</DataTemplate>

How can I set the CommandBindings to the dynamic created TabItem or how do I get the TabItem itself to use my AttachedProperties.RegisterCommandBindings ?

Update

As a workaround (maybe it is the only possible solution) I bind the commands to the TabControl itself

<TabControl ItemsSource="{Binding Path=Workspaces}" 
            local:AttachedProperties.RegisterCommandBindings="{Binding RelativeSource={RelativeSource Self},Path=SelectedItem.CommandBindings}">
    <TabControl.Resources>
        <Style TargetType="TabItem">
            <Setter Property="HeaderTemplate" Value="{StaticResource ClosableTabItemTemplate}"/>
        </Style>
    </TabControl.Resources>
</TabControl>

Answer 1

Did you try to set the attached property of the item container?:

<TabControl ItemsSource="{Binding Path=Workspaces}">
    <TabControl.ItemContainerStyle>
        <Style TargetType="TabItem">
            <Setter Property="local:AttachedProperties.RegisterCommandBindings" Value="{Binding RelativeSource={RelativeSource Self}, Path=CommandBindings}" />
            <Setter Property="HeaderTemplate" Value="{StaticResource ClosableTabItemTemplate}"/>
        </Style>
    </TabControl.ItemContainerStyle>
</TabControl>