action委托的使用

类文件中：

 public class greeting
    {
     


        public void sayhiEnglish(string name)
        {
            Console.WriteLine("hello world,{0}",name);

        }

        public void sayhiChinese(string name)
        {
            Console.WriteLine("good morning,{0}", name);

        }

        public void sayhiAmerican(string name)
        {
            Console.WriteLine("merry christmas,{0}", name);

        }

        public void sayhiET(string name, peopletype type)
        {
            Console.WriteLine("%$^&**,{0}", name);

        }


        public void sayhidelegate(string name,Action<string> act)
        {
            Console.WriteLine("*********");
            act.Invoke(name);
            Console.WriteLine("结束时间"+DateTime.Now+"");
        }






    }

program.cs文件中：

 greeting g = new greeting();
            Action<string> act = g.sayhiAmerican;
            g.sayhidelegate("1998",act);
            g.sayhidelegate("小明",new Action<string>(g.sayhiChinese));

一般委托的使用：委托使用必须保证参数和返回值相同

 public delegate string fly(int a);
 static void Main(string[] args)
        { fly f = new fly(gh);

            Console.WriteLine(f(10));
        }
 public static string gh(int s)
        {
            return (s + 10).ToString();
        }