iOS remote notification trigger

I. system under iOS 10

• It is a method. There is no way to distinguish the specific situation of receiving notification and clicking notification. You can use UIApplicationStateBackground to judge the situation of the front and back office

  // This method will be invoked even if the application was launched or resumed because of the remote notification. The respective delegate methods will be invoked first. Note that this behavior is in contrast to application:didReceiveRemoteNotification:, which is not called in those cases, and which will not be invoked if this method is implemented. !*/
  -  (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult result))completionHandler API_AVAILABLE(ios(7.0));

II. System iOS 10 and above

1. Application in front desk

   • Receipt of notice: decision on presentation

      // 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 __API_AVAILABLE(macos(10.14), ios(10.0), watchos(3.0), tvos(10.0));
     

   • Click notice: App is running, but there is a message in the notice bar

        // 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 application:didFinishLaunchingWithOptions:.

2. Application in the background
 *Receive notification: turn on background mode

 // This method will be invoked even if the application was launched or resumed because of the remote notification. The respective delegate methods will be invoked first. Note that this behavior is in contrast to application:didReceiveRemoteNotification:, which is not called in those cases, and which will not be invoked if this method is implemented. !*/
 -  (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult result))completionHandler API_AVAILABLE(ios(7.0));
 ```

* Click notification
    ``` objc
    // 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 application:didFinishLaunchingWithOptions:.
    - (void)userNotificationCenter:(UNUserNotificationCenter *)center didReceiveNotificationResponse:(UNNotificationResponse *)response withCompletionHandler:(void(^)(void))completionHandler
    ```

1. App exit (kill)

   • Notice received: the notice received here is the method to execute the "App" to receive the message. The application exit (i.e. App kill) program method will not execute, so this situation does not exist

   • Click notification

     // 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 application:didFinishLaunchingWithOptions:.

• Summary: IOS 10 and above systems

  1. Received notice: it is divided into foreground and background modes. The foreground mode can decide the presentation form. The background mode requires engineering configuration Capabilities

     • foreground mode

       // 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.

     • Background mode

       This method will be invoked even if the application was launched or resumed because of the remote notification. The respective delegate methods will be invoked first. Note that this behavior is in contrast to application:didReceiveRemoteNotification:, which is not called in those cases, and which will not be invoked if this method is implemented. !*/

  2. Click notification

    // 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 application:didFinishLaunchingWithOptions:.
    - (void)userNotificationCenter:(UNUserNotificationCenter *)center didReceiveNotificationResponse:(UNNotificationResponse *)response withCompletionHandler:(void(^)(void))completionHandler
    ```