Lambda表达式底层分析

一、我们先看下C#代码下Lamdba表达式的写法

　　// <summary>
    /// 写入日志委托
    /// </summary>
    /// <param name="message">消息</param>
    delegate void WriteLog(string message);
    class Program
    {
        static void Main(string[] args)
        {
            {
                WriteLog method = (message) => { Console.WriteLine(message); };
                method.Invoke("写入日志测试1");
            }
            {
                WriteLog method = (message) => { Console.WriteLine(message); };
                method.Invoke("写入日志测试2");
            }
            Console.ReadKey();
        }
    }

　　

二、再通过反编译工具查看

internal class Program
	{
		[CompilerGenerated]
		[Serializable]
		private sealed class <>c
		{
			public static readonly Program.<>c <>9 = new Program.<>c();

			public static WriteLog <>9__0_0;

			public static WriteLog <>9__0_1;

			internal void <Main>b__0_0(string message)
			{
				Console.WriteLine(message);
			}

			internal void <Main>b__0_1(string message)
			{
				Console.WriteLine(message);
			}
		}

		private static void Main(string[] args)
		{
			WriteLog arg_21_0;
			if ((arg_21_0 = Program.<>c.<>9__0_0) == null)
			{
				arg_21_0 = (Program.<>c.<>9__0_0 = new WriteLog(Program.<>c.<>9.<Main>b__0_0));
			}
			WriteLog writeLog = arg_21_0;
			writeLog("写入日志测试1");
			WriteLog arg_4F_0;
			if ((arg_4F_0 = Program.<>c.<>9__0_1) == null)
			{
				arg_4F_0 = (Program.<>c.<>9__0_1 = new WriteLog(Program.<>c.<>9.<Main>b__0_1));
			}
			WriteLog writeLog2 = arg_4F_0;
			writeLog2("写入日志测试2");
			Console.ReadKey();
		}
	}

三、下面我们来看一组对比图，就非常容易的看出来了

由此我们得出的结论：编译器将lambda表达式生成一个类种类，每个lamdda也会生成一个独立的方法，然后绑定到委托的实例，所谓的lamdba表达式其实只是一个“语法糖”。