C# Case_1 实现用户登录的逻辑

    class Program
    {
        static void Main(string[] args)
        {
            string name, pwd;
            Console.WriteLine("请输入用户名：");
            while (true)
            {
                name = Console.ReadLine();
                if (string.IsNullOrWhiteSpace(name))
                {
                    Console.WriteLine("用户名不能为空！请重新输入：");
                }
                else
                {
                    if (name.Equals("admin"))
                    {
                        Console.WriteLine("请输入密码：");
                        pwd = Console.ReadLine();
                        if (string.IsNullOrEmpty(pwd))
                        {
                            Console.WriteLine("密码不能为空！请重新输入：");
                            pwd = Console.ReadLine();
                        }
                        if (pwd == "123")
                        {
                            Console.WriteLine("登录成功！");
                            break;
                        }
                        else
                        {
                            while (true)
                            {
                                if (string.IsNullOrEmpty(pwd))
                                {
                                    Console.WriteLine("密码不能为空！请重新输入：");
                                }
                                else
                                {
                                    Console.WriteLine("密码输入不正确！请重新输入密码：");
                                }
                                pwd = Console.ReadLine();
                                if (pwd == "123")
                                {
                                    break;
                                }
                            }
                            if (pwd == "123")
                            {
                                Console.WriteLine("登录成功！");
                                break;
                            }
                        }
                    }
                    else
                    {
                        Console.WriteLine("用户名不正确！请重新输入用户名：");
                    }
                }
            }
            Console.ReadKey();
        }
    }