Listing 2: DraggableImage.xaml.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Media;

namespace DragImage {
  public partial class DraggableImage : UserControl {
    public static readonly DependencyProperty SourceProperty =
      DependencyProperty.Register("Source",
      typeof(ImageSource),
      typeof(DraggableImage),
      new PropertyMetadata(null));

    public DraggableImage() {
      InitializeComponent();
    }

    public ImageSource Source {
      set { SetValue(SourceProperty, value); }
      get { return (ImageSource)GetValue(SourceProperty); }
    }

    void OnThumbDragDelta(object sender, DragDeltaEventArgs args) {
      translate.X += args.HorizontalChange;
      translate.Y += args.VerticalChange;
    }
  }
}