New Post: Property Grid - Adding Custom Properties.

<Window x:Class="WpfApplication24.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:xctk="http://schemas.xceed.com/wpf/xaml/toolkit"
        xmlns:local="clr-namespace:WpfApplication24"
        Title="MainWindow" >
    <Grid>
      <StackPanel>
         <xctk:PropertyGrid x:Name="_propertyGrid" Height="400"/>
         <Canvas >
            <local:CanvasItem x:Name="_item" Content="DATA" Left="33" Top="50"/>
         </Canvas>
      </StackPanel>
   </Grid>
</Window>

namespace WpfApplication24
{
  /// <summary>
  /// Interaction logic for MainWindow.xaml
  /// </summary>
  public partial class MainWindow : Window
  {
    public MainWindow()
    {
      InitializeComponent();
      _propertyGrid.SelectedObject = _item;
    }
  }

  public class CanvasItem : ContentControl
  {
    #region LeftProperty
    public static readonly DependencyProperty LeftProperty = DependencyProperty.Register( "Left", typeof( Double ), typeof( CanvasItem ), new UIPropertyMetadata( 0d, OnLeftChanged ) );
    public Double Left
    {
        get { return (Double)GetValue(LeftProperty); }
        set
        {
            SetValue(LeftProperty, value);
        }
    }

    private static void OnLeftChanged( DependencyObject o, DependencyPropertyChangedEventArgs e )
    {
      CanvasItem item = o as CanvasItem;
      if( item != null )
      {
        Canvas.SetLeft( item, ( Double )e.NewValue );
      }
    }
    #endregion

    #region TopProperty
    public static readonly DependencyProperty TopProperty = DependencyProperty.Register( "Top", typeof( Double ), typeof( CanvasItem ), new UIPropertyMetadata( 0d, OnTopChanged ) );
    public Double Top
    {
      get
      {
        return ( Double )GetValue( TopProperty );
      }
      set
      {
        SetValue( TopProperty, value );
      }
    }

    private static void OnTopChanged( DependencyObject o, DependencyPropertyChangedEventArgs e )
    {
      CanvasItem item = o as CanvasItem;
      if( item != null )
      {
        Canvas.SetTop( item, ( Double )e.NewValue );
      }
    }
    #endregion
  }
}