public static TeacherService GetInstance() { if (TeacherServiceObj == null) { TeacherServiceObj = new TeacherService(); } return(TeacherServiceObj); }
//登陆 public bool TeacherLogIn(string loginId, string loginPwd, out Teacher validTeacher) { Teacher teacher = new TeacherService().GetTeacherById(loginId); if (teacher == null) { validTeacher = null; //用户名不存在 return(false); } if (teacher.TeacherPwd == loginPwd) { validTeacher = teacher; return(true); } else { validTeacher = null;//密码错误 return(false); } }