事件demo

 delegate void MoveEventHandle(object source,MoveEventArgs e);
 public class MoveEventArgs:EventArgs
 {
 public int newPosition;
 public bool cancel;
 public MoveEventArgs(int newposition)
 {
 this.newPosition=newposition;
 }
 }
 class Slider
 {
 int position;
 public event MoveEventHandle Move;
 public int Position
 {
 get
 {
 return position;
 }
 set
 {
 if(position!=value)
 {
 if(Move!=null)
 {
 MoveEventArgs args=new MoveEventArgs(value);
 Move(this,args);
 if(args.cancel)
 return;
 }
 position=value;
 }
 }
 }
 }
 class Form
 {
 static void Main()
 {
 Slider slider=new Slider();
 slider.Move+=new MoveEventHandle(slider_Move);
 slider.Position=;
 slider.Position=;
 }
 static void slider_Move(object source,MoveEventArgs  e)
 {
 if(e.newPosition<)
 console.writeline("OK");
 else
 {
 e.Cancle=true;
 console.writeline("Can't go that higjh");
 }
 }
 }