WPF ItemsControl the current ListItem Index in the ItemsSource

Question

Is it possible to know the current item's Index in a ItemsControl?

EDIT This works!

<Window.Resources>

    <x:Array Type="{x:Type sys:String}" x:Key="MyArray">
        <sys:String>One</sys:String>
        <sys:String>Two</sys:String>
        <sys:String>Three</sys:String>
    </x:Array>

</Window.Resources>

<ItemsControl ItemsSource="{StaticResource MyArray}" AlternationCount="100">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <StackPanel Margin="10">

               <!-- one -->
               <TextBlock Text="{Binding Path=., 
                    StringFormat={}Value is {0}}" />

               <!-- two -->
                <TextBlock Text="{Binding Path=(ItemsControl.AlternationIndex), 
                    RelativeSource={RelativeSource TemplatedParent}, 
                    FallbackValue=FAIL, 
                    StringFormat={}Index is {0}}" />

               <!-- three -->
                <TextBlock Text="{Binding Path=Items.Count, 
                    RelativeSource={RelativeSource FindAncestor, 
                        AncestorType={x:Type ItemsControl}}, 
                    StringFormat={}Total is {0}}" />

            </StackPanel>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

It looks like this:

Answer 1

I asked the same thing a while ago here

There isn't a built in Index property, but you can set the AlternationCount of your ItemsControl to something higher than your item count, and bind to the AlternationIndex

<TextBlock Text="{Binding 
    Path=(ItemsControl.AlternationIndex), 
    RelativeSource={RelativeSource Mode=TemplatedParent}, 
    FallbackValue=FAIL, 
    StringFormat={}Index is {0}}" />

It should be noted that this solution may not work if your ListBox uses Virtualization as bradgonesurfing pointed out here.