lambda表达式用法——C#学习笔记

 “Lambda 表达式”是一个匿名函数，它可以包含表达式和语句，并且可用于创建委托或表达式目录树类型。

 实例如下：

代码如下：

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Policy;
using System.Text;
using System.Threading.Tasks;namespace ConsoleApp2
{delegate bool D();delegate bool D2(int i);class Test{D del;D2 del2;public void TestMethod(int input){int j = 0;// Initialize the delegates with lambda expressions.// Note access to 2 outer variables.// del will be invoked within this method.del = () => { j = 10; return j > input; };// del2 will be invoked after TestMethod goes out of scope.del2 = (x) => { return x == j; };// Demonstrate value of j:// Output: j = 0 // The delegate has not been invoked yet.Console.WriteLine("调用前j = {0}", j);// Invoke the delegate.bool boolResult = del();// Output: j = 10 b = TrueConsole.WriteLine("调用后j = {0}. b = {1}", j, boolResult);}static void Main(){Test test = new Test();test.TestMethod(5);// Prove that del2 still has a copy of// local variable j from TestMethod.bool result = test.del2(10);// Output: TrueConsole.WriteLine(result);Console.ReadKey();}}}