out返回值的用法与用途

        static void Main(string[] arr)
        {

            
            Console.WriteLine("请输入用户名");
            string uname = Console.ReadLine();
            Console.WriteLine("请输入密码");
            string upwd = Console.ReadLine();
            string msg;

            //out参数用于返值多个类型不一样，比如同时返回string ,bool,int
            bool bl = IsLogin(uname, upwd, out msg);
            Console.WriteLine("登录结果"+bl);
            Console.WriteLine("登录信息" + msg);
            Console.ReadKey();

        }  
        /// <summary>
        /// 判断登录是否成功
        /// </summary>
        /// <param name="uname">用户名</param>
        /// <param name="upwd">密码</param>
        /// <param name="msg">返回的信息</param>
        /// <returns>返回登录结果</returns>
        public static bool IsLogin(string uname,string upwd,out string msg)
        {
            
            if (uname == "admin" && upwd == "888888")
            {
                msg = "登录成功";
                return true;
            }
            else if (uname == "admin")
            {
                msg = "密码不对";
                return false;
            }
            else
            {
                msg = "用户名不对";
                return false;
                
            }
            
        }