static void Main(string[] args) { Console.WriteLine("请输入用户名^_^"); string userName = Console.ReadLine(); Console.WriteLine("请输入密码o(* ̄︶ ̄*)o"); string userPwd = Console.ReadLine(); StudentDao dao = new StudentDao(); StudentBusiness buiness = new StudentBusiness(); string msg = string.Empty; if (dao.ValidataUser(userName, userPwd, ref msg)) { string email = dao.Login(userName, userPwd); Console.WriteLine("恭喜{0},{1}", email, msg); // 选择 Console.WriteLine("请选择"); // 1、统计学生人数 // 2、查询学生名单 // 3、新增年级 Console.WriteLine("1、统计学生人数"); Console.WriteLine("2、查询学生名单"); Console.WriteLine("3、新增年级"); int choice = int.Parse(Console.ReadLine()); switch (choice) { case 1: Console.WriteLine("统计学生人数"); break; case 2: Console.WriteLine("查询学生名单"); List <Student> students = buiness.GetStudentList(); foreach (var student in students) { Console.WriteLine(student.StudentName + "————" + student.StudentNo); } break; case 3: Console.WriteLine("请输入年级id"); string gradeId = Console.ReadLine(); Console.WriteLine("请输入年级名称"); string gradeName = Console.ReadLine(); int count = buiness.AddGrade(gradeId, gradeName); if (count > 0) { Console.WriteLine("增加成功"); } else { Console.WriteLine("增加失败"); } break; default: break; } } else { Console.WriteLine(msg); } }