Adding a counter to a DataTemplate - xaml

Question

I have a DataTemplate for an ItemsControl that outputs a Grid with some binded controls, and this works as expected.
However, I want the first column of the Grid to output a counter of each Grid made.
For example...
<DataTemplate x:Key="myDataTemplate">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="75" />
<ColumnDefinition Width="150" />
</Grid.ColumnDefinitions>
<TextBlock Text="X" /> <!-- I want a counter to go here -->
<TextBox Grid.Column="1" Text="{Binding Path=Name}" />
</Grid>
</DataTemplate>
I want that first TextBlock to display 1, 2, 3, 4, etc... as the DataTemplate outputs new Grids.
Any ideas on the best way to do that?
Thanks!

Answer 1

You can achieve this using AlternationCount and AlternationIndex of ItemsControl. Like,
<ItemsControl ItemsSource="{Binding Items}" AlternationCount="{Binding Items.Count}">
<ItemsControl.ItemTemplate>
<DataTemplate x:Key="myDataTemplate">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="75" />
<ColumnDefinition Width="150" />
</Grid.ColumnDefinitions>
<TextBlock Text="{Binding Path=(ItemsControl.AlternationIndex), RelativeSource={RelativeSource TemplatedParent}}" />
<TextBox Grid.Column="1" Text="{Binding Path=Name}" />
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
This will give you 0 based index; you can use IValueConverter if any changes needed.