Firebase 消息传递仅在前台有效

Question

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    [UNUserNotificationCenter currentNotificationCenter].delegate = self;
    UNAuthorizationOptions authOptions =
    UNAuthorizationOptionAlert
    | UNAuthorizationOptionSound
    | UNAuthorizationOptionBadge;
    [[UNUserNotificationCenter currentNotificationCenter] requestAuthorizationWithOptions:authOptions completionHandler:^(BOOL granted, NSError * _Nullable error) {

    }];

    [FIRMessaging messaging].remoteMessageDelegate = self;
    [[UIApplication sharedApplication] registerForRemoteNotifications];
    [FIRApp configure];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(tokenRefreshNotification:)
                                                 name:kFIRInstanceIDTokenRefreshNotification object:nil];

    return YES;
}
- (void)applicationWillResignActive:(UIApplication *)application {
}
- (void)applicationDidEnterBackground:(UIApplication *)application {

   [[FIRMessaging messaging] disconnect];
   NSLog(@"Disconnected from FCM");
}
- (void)applicationWillEnterForeground:(UIApplication *)application {

}
- (void)applicationDidBecomeActive:(UIApplication *)application {

    [self connectToFcm];
}
- (void)applicationWillTerminate:(UIApplication *)application {
}


- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo {

    // Print message ID.
    NSLog(@"message 1");
    if (userInfo[kGCMMessageIDKey]) {
        NSLog(@"Message ID: %@", userInfo[kGCMMessageIDKey]);
    }
    // Print full message.
    NSLog(@"%@", userInfo);
}
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo
fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {

    // Print message ID.
    NSLog(@"message 2");
    if (userInfo[kGCMMessageIDKey]) {
        NSLog(@"Message ID: %@", userInfo[kGCMMessageIDKey]);
    }

    NSLog(@"%@", userInfo);
    completionHandler(UIBackgroundFetchResultNewData);
}

- (void)userNotificationCenter:(UNUserNotificationCenter *)center
       willPresentNotification:(UNNotification *)notification
         withCompletionHandler:(void (^)(UNNotificationPresentationOptions))completionHandler {
    NSLog(@"message 3");
    NSDictionary *userInfo = notification.request.content.userInfo;
    if (userInfo[kGCMMessageIDKey]) {
        NSLog(@"Message ID: %@", userInfo[kGCMMessageIDKey]);
    }

    NSLog(@"full data : %@", userInfo);
    completionHandler(UNNotificationPresentationOptionAlert);

}

- (void)userNotificationCenter:(UNUserNotificationCenter *)center
didReceiveNotificationResponse:(UNNotificationResponse *)response
         withCompletionHandler:(void (^)())completionHandler {
    NSDictionary *userInfo = response.notification.request.content.userInfo;
    NSLog(@"message 1");
    if (userInfo[kGCMMessageIDKey]) {
        NSLog(@"Message ID: %@", userInfo[kGCMMessageIDKey]);
    }
    // Print full message.
    NSLog(@"%@", userInfo);
    completionHandler();
}
- (void)applicationReceivedRemoteMessage:(FIRMessagingRemoteMessage *)remoteMessage {
    // Print full message
    NSLog(@"applicationReceivedRemoteMessage  : %@", remoteMessage.appData);
}

- (void)tokenRefreshNotification:(NSNotification *)notification {
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSString *refreshedToken = [[FIRInstanceID instanceID] token];
    NSLog(@"InstanceID token: %@", refreshedToken);
    if(!(refreshedToken== nil)){
        [defaults setValue:refreshedToken forKey:@"FcmToken"];
    }

    [self connectToFcm];

}
- (void)connectToFcm {
    if (![[FIRInstanceID instanceID] token]) {
        return;
    }

    [[FIRMessaging messaging] disconnect];
    [[FIRMessaging messaging] connectWithCompletion:^(NSError * _Nullable error) {
        if (error != nil) {
            NSLog(@"Unable to connect to FCM. %@", error);
        } else {
            NSLog(@"Connected to FCM.");
        }
    }];
}
- (void)application:(UIApplication *)application didFailToRegisterForRemoteNotificationsWithError:(NSError *)error {
    NSLog(@"Unable to register for remote notifications: %@", error);
}

- (void)application:(UIApplication *)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken {
    NSLog(@"APNs token retrieved: %@", deviceToken); 
}
enter code here

当应用程序处于后台模式时，消息不会传入。当应用程序运行时前台模式消息显示在应用程序接收远程消息函数中。我需要在后台模式出现消息时运行一些代码。任何人都可以给我在后台模式下获取通知的解决方案。

Answer 1

在后台时不允许固定连接存在 谨慎的做法是关闭连接。

请在此处找到相同的参考：断开连接((

Firebase 消息传递框架参考

关于聊天应用程序的简单逻辑：套接字连接

通常，聊天应用程序使用套接字连接与其他节点(设备(连接，以在节点之间传输实时信息。当应用进入后台时，套接字连接将断开连接。

FirebaseMessaging 在相同的逻辑上工作，因此不会在后台工作。

要在后台模式下处理消息传输，请使用推送通知的强大功能。

还要标记您的代码：当应用程序进入后台时，您将断开 FIRMessaging 的连接。你已经这样做了，因为FIRMessaging指南中也有同样的指示。

- (void)applicationDidEnterBackground:(UIApplication *)application {
   [[FIRMessaging messaging] disconnect];
   NSLog(@"Disconnected from FCM");
}

作为您问题的替代解决方案：您可能已经分析了Whatapp或Facebook Messagner应用程序。当应用程序进入后台时，他们使用推送通知来提醒用户消息。你也应该这样做。