Bind ItemsControl with ItemsSource to the array index

The simplest way to do this is to add an Index property to you class ;-) Otherwise it can be done using a MultiValueConverter:

<Window x:Class="IndexSpike.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="300" Width="300" xmlns:Converters="clr-namespace:IndexSpike" xmlns:diag="clr-namespace:System.Diagnostics;assembly=WindowsBase" Name="Root" > <Window.Resources> <Converters:GetIndex x:Key="GetIndexConverter"/> </Window.Resources> <StackPanel> <ItemsControl ItemsSource="{Binding Persons}"> <ItemsControl.ItemTemplate> <DataTemplate> <StackPanel> <TextBlock Margin="0,5,0,0"> <TextBlock.Text> <MultiBinding Converter="{StaticResource GetIndexConverter}" StringFormat="Index: {0}"> <Binding Path="."/> <Binding ElementName="Root" Path="Persons"/> </MultiBinding> </TextBlock.Text> </TextBlock> <TextBlock Text="{Binding Name, StringFormat='Name: {0}'}"/> <TextBlock Text="{Binding Age, StringFormat='Age {0}'}"/> </StackPanel> </DataTemplate> </ItemsControl.ItemTemplate> </ItemsControl> </StackPanel> </Window> using System; using System.Collections.ObjectModel; using System.Globalization; using System.Windows; using System.Windows.Data; namespace IndexSpike { public partial class Window1 : Window { public ObservableCollection<Person> Persons { get; set; } public Window1() { Persons=new ObservableCollection<Person> { new Person("Me",20), new Person("You",30) }; InitializeComponent(); DataContext = this; } } public class Person { public Person(string name,int age) { Name = name; Age=age; } public string Name { get; set; } public int Age { get; set; } } public class GetIndex:IMultiValueConverter { #region Implementation of IMultiValueConverter public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture) { var persons = (ObservableCollection<Person>) values[1]; var person = (Person) values[0]; return persons.IndexOf(person); } public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture) { throw new NotImplementedException(); } #endregion } } 

Thanks to this question I found an other way to declare the MultiBinding:

<MultiBinding Converter="{StaticResource GetIndexConverter}" StringFormat="Index: {0}"> <Binding Path="."/> <Binding RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type ItemsControl}}" Path="DataContext.Persons"/> </MultiBinding>