Использование расширения разметки xaml в wpf?

<Window x:Class="WpfApplication3.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApplication3"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <Image Name="image" HorizontalAlignment="Left" Height="282" Margin="18,18,0,0" VerticalAlignment="Top" Width="394" Source="{Binding MySource}"/>
        <Button Name="button" Content="Button" HorizontalAlignment="Left" Margin="432,18,0,0" VerticalAlignment="Top" Width="75" Click="button_Click"/>
    </Grid>
</Window>

using Microsoft.Win32;
using System;
using System.ComponentModel;
using System.Windows;

namespace WpfApplication3
{
    public partial class MainWindow : Window
    {
        public MyClass Class;

        public MainWindow()
        {
            InitializeComponent();

            Class = new MyClass();
            image.DataContext = Class;
        }

        private void button_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog myDialog = new OpenFileDialog();
            if (myDialog.ShowDialog().Value)
                Class.MySource = myDialog.FileName;
        }
    }

    public class MyClass : INotifyPropertyChanged
    {
        private String mySource;
        public String MySource
        {
            get
            {
                return mySource;
            }
            set
            {
                mySource = value;
                OnPropertyChanged("MySource");
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        protected void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}