WPF StringFormat

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication2
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.DataContext = new Foo()
                {
                    Value = "YoMamma",
                    DateValue = DateTime.Now,
                    NumberValue = 3.14m,
                    AmpersandValue = "&"
                };
        }
    }

    public class Foo : INotifyPropertyChanged
    {
        private string _value;
        public string Value
        {
            get { return _value; }
            set { _value = value; FireNpc("Value"); }
        }
        private decimal _numberValue;
        public decimal NumberValue
        {
            get { return _numberValue; }
            set { _numberValue = value; FireNpc("NumberValue"); }
        }
        private DateTime _dateValue;
        public DateTime DateValue
        {
            get { return _dateValue; }
            set { _dateValue = value; FireNpc("DateValue"); }
        }
        // Heh...don't actually do this, naturally...
        private string _ampersandValue;
        public string AmpersandValue
        {
            get { return _ampersandValue; }
            set { _ampersandValue = value; FireNpc("AmpersandValue"); }
        }
        public event PropertyChangedEventHandler PropertyChanged = delegate { };
        private void FireNpc(string name)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(name));
        }
    }
}


<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <StackPanel>
        <!-- should show '#1:Foo & Bar:YoMamma' -->
        <TextBlock Text="{Binding Path=Value, StringFormat=#1:Foo &amp; Bar:{0}}"/>

        <!-- should show '#2:Foo & Bar:YoMamma' -->
        <TextBlock>
            <TextBlock.Text>
                <Binding Path="Value" StringFormat="#2:Foo &amp; Bar:{0}"/>
            </TextBlock.Text>
        </TextBlock>

        <!-- Alternate: should show '#1:Foo & Bar:YoMamma' -->
        <TextBlock Text="{Binding Path=Value, StringFormat=#1:Foo &#38; Bar:{0}}"/>

        <!-- Alternate: should show '#2:Foo & Bar:YoMamma' -->
        <TextBlock>
            <TextBlock.Text>
                <Binding Path="Value" StringFormat="#2:Foo &#38; Bar:{0}"/>
            </TextBlock.Text>
        </TextBlock>

        <!-- will actually show the '{' and '}', so 'Foo & Bar:{0}' -->
        <TextBlock Text="{Binding Path=Value, StringFormat=Foo &amp; Bar:{{0}}}"/>

        <!-- default 'custom' (there's a fun oxymoron) format - should be '$3.14' -->
        <TextBlock Text="{Binding Path=NumberValue, StringFormat=c}"/>

        <!-- custom 'custom' (bear with me) format -->
        <TextBlock Text="{Binding Path=DateValue, StringFormat=MM/dd/yyyy}"/>

        <!-- multi parameter formatting-->
        <TextBlock>
            <TextBlock.Text>
                <MultiBinding StringFormat="As of {2:MM/dd/yyyy}, {0} cost {1:c}">
                    <Binding Path="Value"/>
                    <Binding Path="NumberValue"/>
                    <Binding Path="DateValue"/>
                </MultiBinding>
            </TextBlock.Text>
        </TextBlock>

        <!-- And a crazy-person's method, using multi parameter formatting-->
        <TextBlock>
            <TextBlock.Text>
                <MultiBinding StringFormat="{}{0} {1} {0} = {0}">
                    <Binding Path="Value"/>
                    <Binding Path="AmpersandValue"/>
                </MultiBinding>
            </TextBlock.Text>
        </TextBlock>

    </StackPanel>
</Window>