iOS本地推送（本地通知）

在iOS8之后，以前的本地推送写法可能会出错，接收不到推送的信息，

如果出现以下信息：

1 Attempting to schedule a local notification
2 with an alert but haven't received permission from the user to display alerts
3 with a sound but haven't received permission from the user to play sounds

说明在IOS8下没有注册，所以需要额外添加对IOS8的注册方法，API中有下面这个方法：

// Registering UIUserNotificationSettings more than once results in previous settings being overwritten.
- (void)registerUserNotificationSettings:(UIUserNotificationSettings *)notificationSettings NS_AVAILABLE_IOS(8_0);

这个方法是8.0之后才能使用的，所以需要判断一下系统的版本。

第一步：注册本地通知：

// 设置本地通知
+ (void)registerLocalNotification:(NSInteger)alertTime {
  UILocalNotification *notification = [[UILocalNotification alloc] init];
  // 设置触发通知的时间
  NSDate *fireDate = [NSDate dateWithTimeIntervalSinceNow:alertTime];
  NSLog(@"fireDate=%@",fireDate);

  notification.fireDate = fireDate;
  // 时区
  notification.timeZone = [NSTimeZone defaultTimeZone];
  // 设置重复的间隔
  notification.repeatInterval = kCFCalendarUnitSecond;

  // 通知内容
  notification.alertBody =  @"该起床了...";
  notification.applicationIconBadgeNumber = 1;
  // 通知被触发时播放的声音
  notification.soundName = UILocalNotificationDefaultSoundName;
  // 通知参数
  NSDictionary *userDict = [NSDictionary dictionaryWithObject:@"开始学习iOS开发了" forKey:@"key"];
  notification.userInfo = userDict;

  // ios8后，需要添加这个注册，才能得到授权
  if ([[UIApplication sharedApplication] respondsToSelector:@selector(registerUserNotificationSettings:)]) {
    UIUserNotificationType type =  UIUserNotificationTypeAlert | UIUserNotificationTypeBadge | UIUserNotificationTypeSound;
    UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:type
                                                                             categories:nil];
    [[UIApplication sharedApplication] registerUserNotificationSettings:settings];
    // 通知重复提示的单位，可以是天、周、月
    notification.repeatInterval = NSCalendarUnitDay;
  } else {
    // 通知重复提示的单位，可以是天、周、月
    notification.repeatInterval = NSDayCalendarUnit;
  }

  // 执行通知注册
  [[UIApplication sharedApplication] scheduleLocalNotification:notification];
}

第二步：处理通知，这个是在appdelegate中的代理 方法回调

// 本地通知回调函数，当应用程序在前台时调用
- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification {
  NSLog(@"noti:%@",notification);

  // 这里真实需要处理交互的地方
  // 获取通知所带的数据
  NSString *notMess = [notification.userInfo objectForKey:@"key"];
  UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"本地通知(前台)"
                                                  message:notMess
                                                 delegate:nil
                                        cancelButtonTitle:@"OK"
                                        otherButtonTitles:nil];
  [alert show];

  // 更新显示的徽章个数
  NSInteger badge = [UIApplication sharedApplication].applicationIconBadgeNumber;
  badge--;
  badge = badge >= 0 ? badge : 0;
  [UIApplication sharedApplication].applicationIconBadgeNumber = badge;

  // 在不需要再推送时，可以取消推送
  [HomeViewController cancelLocalNotificationWithKey:@"key"];
}

第三步：在需要的时候取消某个推送

// 取消某个本地推送通知
+ (void)cancelLocalNotificationWithKey:(NSString *)key {
  // 获取所有本地通知数组
  NSArray *localNotifications = [UIApplication sharedApplication].scheduledLocalNotifications;

  for (UILocalNotification *notification in localNotifications) {
    NSDictionary *userInfo = notification.userInfo;
    if (userInfo) {
      // 根据设置通知参数时指定的key来获取通知参数
      NSString *info = userInfo[key];

      // 如果找到需要取消的通知，则取消
      if (info != nil) {
        [[UIApplication sharedApplication] cancelLocalNotification:notification];
        break;
      }
    }
  }
}

下载demo:https://github.com/632840804/LocalPush