C#Lambda和委托

1、Action  委托，没有返回值  

class Program
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
            
            List<int> mylist=new List<int>{0,2,3,4,5};
        //    var mylistEven=mylist.FindAll(p=>p%2==0);
         //多个语句处理参数
             var mylistEven=mylist.FindAll(p=>
                                      {
                                          if(p%2==0)
                                          {
                                              return true;
                                          }
                                          else{
                                              Console.Write(" 奇数"+p);
                                              return false;
                                          }
                                      });
            Console.WriteLine("偶数显示 . . ");
            foreach(int i in mylistEven )
            {
                Console.Write(" "+i);
            }
            Console.WriteLine("   ");
            
//            var args1=new MyArgs();
//            var args2="myEvent";
//            
//            var myEvenHandle=new EventHandler(this,(args1,args2)=>{
//                                              
//                                                  Console.WriteLine("   ");
//                                              });
        
            // disable once SuggestUseVarKeywordEvident
            Action<int ,int > action1= delegate(int a,int b){
                                          
                                   Console.WriteLine(a+"   "+b);
            };
            action1(1,2);
            
            Console.ReadKey(true);
        }
    }
     public class MyArgs:EventArgs
        {
            int age=0;
        }

 2 、Func委托，可以包含返回值

class Program
    {
        static void Main(string[] args)
        {
            Func<int, bool> f1 = IsNumberLessThen5;
            bool flag = f1(4);
            Console.WriteLine(flag);

            //以下是其它的用法，与IsNumberLessThen5作用相同。只是写法不同而已。
            Func<int, bool> f2 = i => i < 5;
            Func<int, bool> f3 = (i) => { return i < 5; };
            Func<int, bool> f4 = delegate(int i) { return i < 5; };
            flag = f2(4); Console.WriteLine(flag);
            flag = f3(4); Console.WriteLine(flag);
            flag = f4(4); Console.WriteLine(flag);            

            Console.ReadLine();
        }

        private static bool IsNumberLessThen5(int number)
        {
            if (number < 5)
                return true;
            return false;
        }
    }