C# Lambda

        private void DoNothing()
        {
            Console.WriteLine("This is DoNothing");
        }

        private void Study(int id, string name)
        {
            Console.WriteLine($"{id} {name} 正在学习");
        }

        public delegate void NoReturnNoPara();
        public delegate void NoReturnWithPara(int x, string y);//1 声明委托
        public delegate int WithReturnNoPara();
        public delegate string WithReturnWithPara(out int x, ref int y);

           {
                //.NetFramework1.0  1.1
                NoReturnNoPara method = new NoReturnNoPara(this.DoNothing);
            }

            {
                //.NetFramework2.0  匿名方法，delegate关键字
                //可以访问局部变量
                NoReturnWithPara method = new NoReturnWithPara(delegate (int id, string name)
                {
                    Console.WriteLine(i);
                    Console.WriteLine($"{id} {name} 正在学习");
                });
                method.Invoke(1, "name");
            }

            {
                //.NetFramework3.0   把delegate关键字去掉，增加了一个箭头=>
                //lambda表达式  参数列表=>方法体
                NoReturnWithPara method = new NoReturnWithPara(
                    (int id, string name) =>
                {
                    Console.WriteLine($"{id} {name} 正在学习");
                });
                method.Invoke(123, "aaa");
            }

           {
                NoReturnWithPara method = new NoReturnWithPara(
                    (id, name) =>//省略参数类型，编译器的语法糖，虽然没写，编译时还是有的，根据委托推算
                    {
                        Console.WriteLine($"{id} {name} 正在学习");
                    });
                method.Invoke(123, "bbb");
            }

           {
                NoReturnWithPara method = new NoReturnWithPara(
                    (id, name) => Console.WriteLine($"{id} {name} 正在学习"));
                //如果方法体只有一行，可以去掉大括号和分号
                method.Invoke(123, "ccc");
            }

           {
                NoReturnWithPara method = (id, name) => Console.WriteLine($"{id} {name} 正在学习");
                method.Invoke(123, "ddd"); //new NoReturnWithPara可以省掉，也是语法糖，编译器自动加上
            }