委托（匿名函数、Lambda表达式）

?

using System;

 

namespace ConsoleApp1

{

    /// <summary>

    /// 委托（匿名函数、Lambda表达式）

    /// </summary>

    class Program

    {

 

        //定义委托

        internal delegate void TestDelegate(string s);

        static void Main(string[] args)

        {

            Func<string> f1 = () => "Jeff";

            //var result= f1();

            

            //.net2.0时期的匿名函数写法

            Func<string> f2 = delegate () { return "Jeff2"; };

            //var result = f2.Invoke();

 

            //.net3.0以后的Lambda表达式写法

            //Func<Int32, string> f3 = (Int32 i) => i.ToString();

            Func<Int32, string> f3 = (i) => i.ToString();

            var result = f3(100);

 

            Func<Int32, string> f4 = delegate (Int32 i) { return i.ToString(); };

            //var result = f4(1000);

 

            //Console.WriteLine(result);

            //Console.ReadKey();

 

            //1.实例化委托

            TestDelegate testDelegate1 = new TestDelegate(ConsoleStr);

            testDelegate1("测试委托1");

 

            //2.匿名委托（.NET2.0 +）

            TestDelegate testDelegate2 = delegate (string s) { Console.WriteLine(s); };

            testDelegate2.Invoke("测试委托2");

 

            //3.Lambda表达式

            TestDelegate testDelegate3 = (s) => { Console.WriteLine(s); };

            testDelegate3("测试委托3"); 

        }

 

        static void ConsoleStr(string s)

        {

            Console.WriteLine(s);

        }

}

}