/// <summary>
        /// 声明委托
        /// </summary>
        public delegate void BuyGoodsDelegate(string Name);
        /// <summary>
        /// 委托的方法
        /// </summary>
        public void BuyGoods(string Name)
        {
            Console.WriteLine($"小明让我去买{Name}");
        }

//委托和方法关联
BuyGoodsDelegate buyGoods = new BuyGoodsDelegate(BuyGoods);

//调用方式1
buyGoods("鞋子");
//调用方式2
buyGoods.Invoke("衣服");

        //委托和方法关联
        Func<Student, string> funcNew = FuncTestDelegate;

        /// <summary>
        /// string返回类型方法
        /// </summary>
        /// <param name="student"></param>
        /// <returns></returns>
        public string FuncTestDelegate(Student student)
        {
            return student.StudentName;
        }

            //Func 匿名函数  
            Func<int,int,string> func3 = delegate(int num1,int num2)
            {
                return $"Func:总和：{num1+ num2}";
            };
            //调用
            var result = func3(10, 20);

            //Func lamda表达式  无参数
            Func<string> func1 = () =>
            {
                return "Func:你好";
            };
            var result = func1();

            //Func lamda表达式  有参数
            string aa = "ABC";
            string bb = "DEF";
            Func<string, string, string> func2 = (p1, p2) =>
            {
                return $"Func:{p1},你好{p2}";
            };
            result = func2(aa, bb);

            //Action  lamda表达式
            Action<string, string> action = (p1, p2) =>
            {
                Console.Write($"Action:{p1},你好{p2}");
            };
            action("ABC", "DEF");