iOS 通知分类：

1. remote-notification

   • silent remote notifications

   iOS 7在推送方面最大的变化就是允许，应用收到通知后在后台（background）状态下运行一段代码，可用于从服务器获取内容更新。功能使用场景：（多媒体）聊天，Email更新，基于通知的订阅内容同步等功能，提升了终端用户的体验。
   Remote Notifications 与之前版本的对比可以参考下面两张 Apple 官方的图片便可一目了然。
   
   
   如果只携带content-available: 1 不携带任何badge，sound 和消息内容等参数，则可以不打扰用户的情况下进行内容更新等操作即为“Silent Remote Notifications”。
   

   若有content-available: 1 字段并带有任何badge，sound 和消息内容等参数一个或多个，都会在手机端有一个的表现行式（如声单，提示框，badge 并会调用：[UIApplicationDelegate application:didReceiveRemoteNotification:fetchCompletionHandler:]方法
   若只带content-available: 1字段只会调用[UIApplicationDelegate application:didReceiveRemoteNotification:fetchCompletionHandler:],在手机端没有其他的表现。

2. 不同版本的通知注册及回调用情况

   1. iOS8 以前

      [[UIApplication sharedApplication] registerForRemoteNotificationTypes:(UIRemoteNotificationTypeBadge | UIRemoteNotificationTypeSound | UIRemoteNotificationTypeAlert)];
      

   2. iOS8~iOS9

      UIUserNotificationSettings * settings = [UIUserNotificationSettings settingsForTypes:( UIUserNotificationTypeBadge | UIUserNotificationTypeSound | UIUserNotificationTypeAlert)      categories:nil];
      [[UIApplication sharedApplication] registerUserNotificationSettings:settings];
      
      [[UIApplication sharedApplication] registerForRemoteNotifications];
      

      3. iOS10

         // iOS10.0 register remote notification
         [[UIApplication sharedApplication]registerForRemoteNotifications];
         [[UNUserNotificationCenter currentNotificationCenter]requestAuthorizationWithOptions:UNAuthorizationOptionAlert|UNAuthorizationOptionBadge|UNAuthorizationOptionSound completionHandler:^(BOOL granted, NSError * _ Nullable error) {
         if (granted) {
            [UNUserNotificationCenter currentNotificationCenter].delegate= self;
         }
         
         }];
         }
         

         在iOS10，苹果将用户通知相关操作集合在了UserNotifications.framework中，通知的回调用采用代理方式。

    注册通知成功后，Token的获取回调用：
    ```objc
    - (void)application:(UIApplication *)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken NS_AVAILABLE_IOS(3_0){
      NSString * strDeviceToken =[[deviceToken description] stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"< >"]];
      NSLog(@"APNS token:%@", strDeviceToken);
    }
    ```
    注册通知失败的回调用：
    ```objc
    - (void)application:(UIApplication *)application didFailToRegisterForRemoteNotificationsWithError:(NSError *)error NS_AVAILABLE_IOS(3_0);
    ```
    接收到通知的回调用处理方法：
    iOS10以前：
    ```objc
    // 接收到远程通知
    - (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo;
    // 接收到本地通知
    - (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification ；
    ```
    iOS10的回调：
    实现UNUserNotificationCenterDelegate的代理方法：这些代理方法是可选的。
    ```objc
    // The method will be called on the delegate only if the application is in the foreground. If the method is not implemented or the handler is not called in a timely manner then the notification will not be presented. The application can choose to have the notification presented as a sound, badge, alert and/or in the notification list. This decision should be based on whether the information in the notification is otherwise visible to the user.
    - (void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions options))completionHandler __IOS_AVAILABLE(10.0) __TVOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0);


    // The method will be called on the delegate when the user responded to the notification by opening the application, dismissing the notification or choosing a UNNotificationAction. The delegate must be set before the application returns from applicationDidFinishLaunching:.
    - (void)userNotificationCenter:(UNUserNotificationCenter *)center didReceiveNotificationResponse:(UNNotificationResponse *)response withCompletionHandler:(void(^)())completionHandler __IOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0) __TVOS_PROHIBITED{

      NSDictionary * userinfo= response.notification.request.content.userInfo;
        [self analysisNotification:userinfo];
        // TODO:: 如果有用户操作，可获取到对应的动作类型，并进行相关处理、
        // 例如
            if ([response.notification.request.content.categoryIdentifier isEqualToString:@"replaymessage"]) {
       UNTextInputNotificationResponse * tresponse =(UNTextInputNotificationResponse*)response;
       NSLog(@"%@",tresponse.userText);
        //        get the user input text to dosomething

   }

    }

    ```