登录验证的三种方式(控制台)

第一种方式：

            while (true)

            {

                Console.WriteLine("请输入用户名：");

                string uid = Console.ReadLine();

                Console.WriteLine("请输入密码");

                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 "登录成功";

            }

            else if (uid == "admin")

            {

                return "密码错误！";

            }

            else

            {

                return "用户名错误!";

            }

        }

第二种方式：

            while (true)

            {

                Console.WriteLine("请输入用户名：");

                string uid = Console.ReadLine();

                Console.WriteLine("请输入密码：");

                string pwd = Console.ReadLine();

                string msg;

                if (CL(uid, pwd, out msg))

                {

                    Console.WriteLine("登录成功");

                }

                else

                {

                    Console.WriteLine("登录失败，错误原因为：{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 = "密码错误";

            }

            else

            {

                msg = "用户名错误";

            }

            return false;

        }

第三种方式：

//与类平行

enum CK

    {

        Secuss,

        Nouid,

        Nopwd

    }

 

    while (true)

            {

                Console.WriteLine("请输入用户名：");

                string uid = Console.ReadLine();

                Console.WriteLine("请输入密码：");

                string pwd = Console.ReadLine();

                switch (Check(uid, pwd))

                {

                    case CK.Secuss:

                        Console.WriteLine("登录成功");

                        break;

                    case CK.Nouid:

                        Console.WriteLine("用户名不存在");

                        break;

                    case CK.Nopwd:

                        Console.WriteLine("密码错误");

                        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;

            }

        }