WPF实现画线动画效果

/// <summary> 
  /// Window2.xaml 的交互逻辑 
  /// </summary> 
  public partial class Window2 : Window 
  { 
    public Window2() 
    { 
      InitializeComponent(); 
      var canvas = new Canvas(); 
      Content = canvas; 
      var points = 
        new List<Point>() 
        { 
          new Point(10, 10), 
          new Point(90, 90), 
          new Point(60, 10), 
          new Point(250, 90), 
          new Point(10, 10) 
        }; 
      var sb = new Storyboard(); 
      for (int i = 0; i < points.Count - 1; i++) 
      { 
        var lineGeometry = new LineGeometry(points[i], points[i]); 
        var path = 
          new Path() 
          { 
            Stroke = Brushes.Black, 
            StrokeThickness = 2, 
            Data = lineGeometry 
          }; 
        canvas.Children.Add(path); 
        var animation = 
          new PointAnimation(points[i], points[i + 1], new Duration(TimeSpan.FromMilliseconds(1000))) 
          { 
            BeginTime = TimeSpan.FromMilliseconds(i  1010) 
          }; 
        sb.Children.Add(animation); 
        RegisterName("geometry" + i, lineGeometry); 
        Storyboard.SetTargetName(animation, "geometry" + i); 
        Storyboard.SetTargetProperty(animation, new PropertyPath(LineGeometry.EndPointProperty)); 
      } 
      MouseDown += (s, e) => sb.Begin(this); 
    } 
  }