登錄驗證的三種方式(控制檯)

第一種方式：

            while (true)
            {
                Console.WriteLine("請輸入用戶名：");
                string uid = Console.ReadLine();
                Console.WriteLine("請輸入密碼");
                string pwd = Console.ReadLine();
                string str = CheckLogin(uid, pwd);
                Console.WriteLine(str);
            }

        public static string CheckLogin(string uid, string pwd)
        {
            if (uid == "admin" && pwd == "888888")
            {
                return "登錄成功";
            }
            else if (uid == "admin")
            {
                return "密碼錯誤！";
            }
            else
            {
                return "用戶名錯誤!";
            }
        }

第二種方式：

            while (true)
            {
                Console.WriteLine("請輸入用戶名：");
                string uid = Console.ReadLine();
                Console.WriteLine("請輸入密碼：");
                string pwd = Console.ReadLine();
                string msg;
                if (CL(uid, pwd, out msg))
                {
                    Console.WriteLine("登錄成功");
                }
                else
                {
                    Console.WriteLine("登錄失敗，錯誤原因爲：{0}", msg);
                }
            }

        public static bool CL(string uid,string pwd,out string msg)
        {

            if (uid == "admin" && pwd == "888888")
            {

                msg = null;
                return true;
            }
            else if (uid == "admin")
            {

                msg = "密碼錯誤";
            }
            else
            {
                msg = "用戶名錯誤";
            }
            return false;
        }

第三種方式：

//與類平行

enum CK
    {
        Secuss,
        Nouid,
        Nopwd
    }

 

    while (true)
            {
                Console.WriteLine("請輸入用戶名：");
                string uid = Console.ReadLine();
                Console.WriteLine("請輸入密碼：");
                string pwd = Console.ReadLine();
                switch (Check(uid, pwd))
                {
                    case CK.Secuss:
                        Console.WriteLine("登錄成功");
                        break;
                    case CK.Nouid:
                        Console.WriteLine("用戶名不存在");
                        break;
                    case CK.Nopwd:
                        Console.WriteLine("密碼錯誤");
                        break;
                }
            }

    public static CK Check(string uid, string pwd)
        {
            if (uid == "admin" && pwd == "888888")
            {
                return CK.Secuss;
            }
            else if (uid == "admin")
            {
                return CK.Nopwd;
            }
            else
            {
                return CK.Nouid;
            }
        }