委托demo

 delegate bool Filter(string s);
 class test
 {
 static void Main()
 {
 Filter f=new Filter(A);
 Display(new string[]{"ant","line","yok"},f);
 }
 static bool A(string s)
 {
 return "N".CompareTo(s)>;
 }
 static void Display(string[] Names,Filter f)
 {
 int count=;
 foreach(string str in Names)
 if(f(str))
 console.writeline("Item {0} is {1}",count++,str);
 }
 }

2.组播委托

 delegate void methodinvoker();
 class test
 {
 static void Main()
 {
 new test();
 }
 test()
 {
 methodinvoker m=null;
 m+=new methodinvoker(Foo);
 m+=new methodinvoker(Goo);
 m();
 }
 void Foo()
 {
 console.writeline("Foo");
 }
 void Goo()
 {
 console.writeline("Goo");
 }
 }

委托能处理的事情接口也能同样处理

  interface IFilter
 {
 bool Filter(string s);
 }
  class test
 {
 class A:IFilter
 {
 public bool Filter(string s)
 {
 return "N".CompareTO(s)>;
 }
 static void Main()
 {
 A a=new A();
 Display(new string[]{"ant","lion","yok"},IFilter f);
 }
 static void Display(string[] Names,IFilter f)
 {
 int count=;
 foreach(string s in Names)
 if(f(s))
 console.writeline("Item {0} is {1}",count++,s);
 }
 }
 }

注：委托处理虽然根漂亮，但委托最好用在事件上。