Обработчик события

 public void startmove(Canvas cnv)
        {
            NameScope.SetNameScope(cnv, new NameScope());
            TranslateTransform animatedTranslateTransform = new TranslateTransform();
            cnv.RegisterName("AnimatedTranslateTransform", animatedTranslateTransform);
            el.RenderTransform = animatedTranslateTransform;
            double k = 0, b = 0;
            k = (end.Y - start.Y) / (end.X - start.X);
            b = end.Y - k * end.X;
            end.X = 800;end.Y = k * 800 + b;
            double dist = Math.Sqrt(Math.Pow(end.Y - start.Y, 2) + Math.Pow(end.X - start.X, 2));
            PathGeometry animationPath = new PathGeometry();
            PathFigure pFigure = new PathFigure();
            pFigure.StartPoint = new Point(start.X-4,start.Y-4);
            LineSegment line = new LineSegment();
            line.Point = end;
            pFigure.Segments.Add(line);
            animationPath.Figures.Add(pFigure);
            animationPath.Freeze();
            DoubleAnimationUsingPath translateXAnimation = new DoubleAnimationUsingPath();
            translateXAnimation.PathGeometry = animationPath;
            translateXAnimation.Duration = TimeSpan.FromSeconds(dist/speed);
            translateXAnimation.Source = PathAnimationSource.X;
            Storyboard.SetTargetName(translateXAnimation, "AnimatedTranslateTransform");
            Storyboard.SetTargetProperty(translateXAnimation, new PropertyPath(TranslateTransform.XProperty));
            DoubleAnimationUsingPath translateYAnimation = new DoubleAnimationUsingPath();
            translateYAnimation.PathGeometry = animationPath;
            translateYAnimation.Duration = TimeSpan.FromSeconds(dist/speed);
            translateYAnimation.Source = PathAnimationSource.Y;
            Storyboard.SetTargetName(translateYAnimation, "AnimatedTranslateTransform");
            Storyboard.SetTargetProperty(translateYAnimation, new PropertyPath(TranslateTransform.YProperty));
            Storyboard pathAnimationStoryboard = new Storyboard();
            //pathAnimationStoryboard.RepeatBehavior = RepeatBehavior.Forever;
            pathAnimationStoryboard.Children.Add(translateXAnimation);
            pathAnimationStoryboard.Children.Add(translateYAnimation);
            pathAnimationStoryboard.Begin(cnv,true);
        }