-(void)viewWillAppear:(BOOL)animated{

    [super viewWillAppear:YES];     //接收后台到前台的通知，更新开关状态     [[NSNotificationCenter defaultCenter] addObserver:self                                              selector:@selector(imcomingBack)                                                  name:UIApplicationDidBecomeActiveNotification object:nil]; } -(void)viewWillDisappear:(BOOL)animated{     [super viewWillDisappear:YES];     [[NSNotificationCenter defaultCenter] removeObserver:self];//移除通知 }          -  (void)imcomingBack{//从后台回来后刷新开关状态     if (IAIOS7) {         [UserModel shareInstance].isOpenNoti = (UIRemoteNotificationTypeNone != [[UIApplication sharedApplication] enabledRemoteNotificationTypes]);     }else{         [UserModel shareInstance].isOpenNoti = (UIUserNotificationTypeNone != [[UIApplication sharedApplication] currentUserNotificationSettings].types);     }     [self.userView.tableView reloadData]; }