委托

            Action<string> greet = name =>//无返回值所以Action<输入类型>
            {
                string greeting = $"Hello {name}!";
                Console.WriteLine(greeting);
            };
            greet("World");//调用

            Func<int,string,string> as1 = (int age, string namf) => namf;//有返回值所以Action<输入类型，。。。，输出类型>
            Console.WriteLine(as1(12,"a"));
            Console.ReadLine();