/*用户收取收件箱*/
 public AllMessage MessageInbox(string userID, string password, DateTime? startDate, DateTime? endDate) {
     UserService userService = new UserService();
     UserInfo userInfo = userService.Login(userID, password);
     if (userInfo.ErrorMessage == null) {
         return userService.MessageInbox(startDate, endDate);
     }
     else {
         AllMessage allMessage = new AllMessage();
         allMessage.ErrorMessage = userInfo.ErrorMessage;
         return allMessage;
     }
 }