class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                Console.WriteLine("====登录和注册：请选择=========");
                Console.WriteLine("    1.登录    2. 注册      ");
                Console.WriteLine("=============================");
                Console.WriteLine("请选择：");
                string input = Console.ReadLine();
                //判断是否在D盘有user.txt文件
                if (!File.Exists(@"D:\user.txt"))
                {
                    FileStream fs = File.Create(@"D:\user.txt");
                    fs.Close();
                    fs.Dispose();
                }
                switch (input)
                {
                    case "1":
                        Console.WriteLine("请输入登录用户名：");
                        string loginName = Console.ReadLine();
                        Console.WriteLine("请输入登录密码：");
                        string loginPwd = Console.ReadLine();
                        StreamReader sr2 = new StreamReader(@"D:\user.txt");
                            while (!sr2.EndOfStream)
                            {
                                string[] user = sr2.ReadLine().Split('-');
                                if (user.Length == 2)
                                {
                                    //获取这个用户名
                                    string name = user[0];
                                  if(name!=loginName){
                                      continue;
                                  }
                                    string pwd = user[1];
                                    //
                                    if (name==loginName && pwd == loginPwd)
                                    {
                                        Console.WriteLine("登录成功！");
                                        Console.ReadKey();

                                    }
                                    else
                                    {
                                        Console.WriteLine("账号密码错误！");
                                         Console.ReadKey();
                                    }
                                }

                            
                        }


                        sr2.Close();
                        sr2.Dispose();
                        break;
                    case "2":
                        Console.WriteLine("请输入注册用户名：");
                        string regName = Console.ReadLine();
                        Console.WriteLine("请输入注册密码：");
                        string regPwd = Console.ReadLine();
                        
                      
                        //读取文件中信息，查看有没有存在的用户名
                        StreamReader sr = new StreamReader(@"D:\user.txt");
                        while (!sr.EndOfStream)
                        {
                            if (sr.ReadLine().IndexOf(regName) != -1)
                            {
                                Console.WriteLine("用户名已存在，请重新输入");
                                Console.ReadKey();
                                return;
                            }
                        }
                        sr.Close();
                        sr.Dispose();

                        //写入注册信息
                        StreamWriter sw = new StreamWriter(@"D:\user.txt",true);
                        sw.WriteLine(regName+'-'+regPwd);
                        sw.Close();
                        sw.Dispose();
                        Console.WriteLine("注册成功！");
                        break;
                    default:
                        Console.WriteLine("请输入正确信息！");
                        break;

                }
            }
            

        }
    }