关于silverlight程序中border(可以是其他的)控件缓慢移动的程序编写解决办法

关于silverlight程序中border(可以是其他的)控件缓慢移动的程序编写
我在网上下了一个程序，但是我并不能完全理解，希望高手能帮帮忙，做一下注释，特别是private void Clock_Tick(object sender, EventArgs e)函数，其次是越详细越好，代码如下：



  public partial class MainPage : UserControl
  {
  private Point mouseStart; //鼠标开始移动的位置
  private Point mouseNow; //鼠标现在的所在位置
  private DispatcherTimer clock; //定义一个计时器
  private bool isMouseDown; //是否按下了鼠标
  double left = 0.0;
  public MainPage()
  {
  InitializeComponent();
  }

  //图片开始移动
  private void border_MouseMove(object sender, MouseEventArgs e)
  {
  if (isMouseDown)
  {
  if (!this.clock.IsEnabled)
  {
  this.clock.Start(); //计时开始
  }
  this.mouseNow = e.GetPosition(this); //获取当前位置
  }
  }

  private void border_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
  {
  isMouseDown = true;
  border.CaptureMouse();
  mouseStart = mouseNow = e.GetPosition(this);
  if (this.clock == null)
  {
  this.clock = new DispatcherTimer();
  this.clock.Interval = new TimeSpan(0, 0, 0, 0, 10);
  this.clock.Tick += new EventHandler(Clock_Tick);
  clock.Start();
  }
  else
  {
  clock.Stop();
  clock.Start();
  }
  }

  private void border_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
  {
  border.ReleaseMouseCapture(); //移除鼠标扑获
  isMouseDown = false;  
  }

  private void Clock_Tick(object sender, EventArgs e)
  {
  const double friction = 0.15;
  left+=((this.mouseNow.X - this.mouseStart.X) * friction) / 2.2;
  border.SetValue(Canvas.LeftProperty, left);
  this.mouseStart.X += ((this.mouseNow.X - this.mouseStart.X) * friction);
  this.mouseStart.Y += ((this.mouseNow.Y - this.mouseStart.Y) * friction);
  if ((Math.Abs(this.mouseNow.X - this.mouseStart.X) < 2) && (Math.Abs(this.mouseNow.Y - this.mouseStart.Y) < 2))
  {
  this.clock.Stop();
  }
  }
  }

[解决办法]

C# code

private void Clock_Tick(object sender, EventArgs e)  {  const double friction = 0.15; //定义常量  left+=((this.mouseNow.X - this.mouseStart.X) * friction) / 2.2; //设置左边的定位位置  border.SetValue(Canvas.LeftProperty, left);//设置 border的属性 第一个参数Canvas.LeftProperty 是Canvas这个空间 LeftProperty 左边的属性 第二参数 是 值 意思是 定位 border在Canvas容器中的位置  this.mouseStart.X += ((this.mouseNow.X - this.mouseStart.X) * friction);//x坐标运算  this.mouseStart.Y += ((this.mouseNow.Y - this.mouseStart.Y) * friction);//y坐标运算  if ((Math.Abs(this.mouseNow.X - this.mouseStart.X) < 2) && (Math.Abs(this.mouseNow.Y - this.mouseStart.Y) < 2))//条件判断  {  this.clock.Stop();//计时器停止  }  }
[解决办法]
 public partial class MainPage : UserControl
   {
       private Point mouseStart; //鼠标开始移动的位置
       private Point mouseNow; //鼠标现在的所在位置
       private DispatcherTimer clock; //定义一个计时器 
 
       private bool isMouseDown; //是否按下了鼠标
       double left = 0.0;
       public MainPage()
       {
           InitializeComponent();
       }

       //图片开始移动
       private void border_MouseMove(object sender, MouseEventArgs e)
       {
           if (isMouseDown)
           {
               if (!this.clock.IsEnabled)
               {
                   this.clock.Start(); //计时开始
               }
               this.mouseNow = e.GetPosition(this); //获取当前位置
           }
       }

       private void border_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
       {
           isMouseDown = true;//设置标志，当前鼠标已经按下
           border.CaptureMouse();//启用对象的鼠标捕获
           mouseStart = mouseNow = e.GetPosition(this);//获取鼠标当前的位置
           if (this.clock == null)//如果Timer为空则新建一个Timer，并且为Timer绑定事件
           {
               this.clock = new DispatcherTimer();
               this.clock.Interval = new TimeSpan(0, 0, 0, 0, 10);//10毫秒执行一次
               this.clock.Tick += new EventHandler(Clock_Tick);//注册事件
               clock.Start();//开始
           }
           else
           {
               clock.Stop();//如果检测到不为空则停止，并且进行下一次启动
               clock.Start();
           }
       }

       private void border_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
       {
           border.ReleaseMouseCapture(); //移除鼠标扑获
           isMouseDown = false;
       }

       private void Clock_Tick(object sender, EventArgs e)
       {
           const double friction = 0.15;//常量
           left += ((this.mouseNow.X - this.mouseStart.X) * friction) / 2.2;//获取左侧偏移量
           border.SetValue(Canvas.LeftProperty, left);//设置当前偏移量位置，让Border动起来
           this.mouseStart.X += ((this.mouseNow.X - this.mouseStart.X) * friction);//不断增加
           this.mouseStart.Y += ((this.mouseNow.Y - this.mouseStart.Y) * friction);
           if ((Math.Abs(this.mouseNow.X - this.mouseStart.X) < 2) && (Math.Abs(this.mouseNow.Y - this.mouseStart.Y) < 2))
           {
               this.clock.Stop();//在某一些情况下Timer停止
           }
       }
   }