Drag and drop with Rx

DandD.cs

var mouseDown = Observable.FromEventPattern<MouseButtonEventArgs>(this, "MouseDown")
                .Select(x => x.EventArgs.GetPosition(this));

            var mouseUp = Observable.FromEventPattern<MouseButtonEventArgs>(this, "MouseUp")
                .Select(x => x.EventArgs.GetPosition(this));

            var mouseMove = Observable.FromEventPattern<MouseEventArgs>(this, "MouseMove")
                .Select(x => x.EventArgs.GetPosition(this));

            mouseMove.SkipUntil(mouseDown)
                .TakeUntil(mouseUp)
                .Subscribe(x =>
            {
                output.Text += string.Format("Drag&Drop yeah. {0}", x);
            });