使用 Xcode/Objective C 订阅 FCM 主题的问题答案

【问题标题】：Issue subscribing to FCM topic using Xcode/Objective C使用 Xcode/Objective C 订阅 FCM 主题的问题
【发布时间】：2018-01-04 04:08:22
【问题描述】：

我有一个无法解决的问题。我对iOS/Xcode的了解有限，请见谅。

我正在尝试使用 xcode/Objective C 订阅 iOS 应用程序的 FCM 主题，但是在加载应用程序时，它没有订阅该主题，在调试器中它甚至看起来都不像在尝试。

如果我移动[[FIRMessaging messaging] subscribeToTopic:@"/topics/channel"]; 行到正下方

[FIRMessaging messaging].delegate = self;
[application registerForRemoteNotifications];
[FIRApp configure];

（及以上return YES;）然后至少我收到此错误消息，表明它至少正在尝试。

2018-01-04 04:00:18.723760+0000 App[1049:1251125] [Firebase/Messaging][I-FCM002010] Cannot subscribe to topic: /topics/channel with token: (null)

所以按照here（和其他一些地方）的建议，我试图将它移到didRegisterUserNotificationSettings，但它似乎根本没有做任何事情，而且在调试器。

这是我完整的 AppDelegate.m 代码

//
//  AppDelegate.m
//

#import "AppDelegate.h"
#import <UserNotifications/UserNotifications.h>
#import <Firebase/Firebase.h>
#import <FirebaseMessaging/FirebaseMessaging.h>
#import <FirebaseInstanceID/FirebaseInstanceID.h>
#import <AFNetworking/AFNetworking.h>
@import Firebase;
@interface AppDelegate () <UNUserNotificationCenterDelegate, FIRMessagingDelegate>

@end

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    [self setupNetworkReachability];

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

    }];

    [FIRMessaging messaging].delegate = self;
    [application registerForRemoteNotifications];
    [FIRApp configure];
    //[[FIRMessaging messaging] subscribeToTopic:@"/topics/channel"];
    return YES;
}

- (void)application:(UIApplication *)application didRegisterUserNotificationSettings:(UNNotificationSettings *)notificationSettings
{
    [[FIRMessaging messaging] subscribeToTopic:@"/topics/channel"];
    NSLog(@"Topic Registered");
}

- (void)applicationWillResignActive:(UIApplication *)application
{

}

- (void)applicationDidEnterBackground:(UIApplication *)application
{

}

- (void)applicationWillEnterForeground:(UIApplication *)application
{

}

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

}

- (void)applicationWillTerminate:(UIApplication *)application
{

}

#pragma mark - Public Methods

+ (AppDelegate *)sharedAppDelegate
{
    return (AppDelegate *)[[UIApplication sharedApplication] delegate];
}

- (void)setupNetworkReachability
{
    [[AFNetworkReachabilityManager sharedManager] setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status)
     {
         if (status == AFNetworkReachabilityStatusReachableViaWiFi || status == AFNetworkReachabilityStatusReachableViaWWAN)
             self.isNetworkAvailable = YES;
         else
             self.isNetworkAvailable = NO;

         NSLog(@"Reachability: %@", AFStringFromNetworkReachabilityStatus(status));
     }];

    [[AFNetworkReachabilityManager sharedManager] startMonitoring];
}

#pragma mark - FIRMessagingDelegate Methods

- (void)messaging:(nonnull FIRMessaging *)messaging didReceiveMessage:(nonnull FIRMessagingRemoteMessage *)remoteMessage
{
    NSLog(@"%@", remoteMessage.appData);
}

- (void)applicationReceivedRemoteMessage:(nonnull FIRMessagingRemoteMessage *)remoteMessage
{
    NSLog(@"%@", remoteMessage.appData);
}

- (void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions options))completionHandler
{
    NSLog(@"%@", notification.request.content.userInfo);
    completionHandler(UNNotificationPresentationOptionAlert + UNNotificationPresentationOptionSound);
}

@end

不胜感激。谢谢。

只是为了更新，App已经直接从FCM控制台接收消息，所以这部分工作正常，只是主题订阅失败了。

【问题讨论】：

你不应该调用[FIRApp配置]； [FIRMessaging 消息].delegate = self;也尝试在 func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {

标签： ios objective-c firebase firebase-cloud-messaging

【解决方案1】：

1：你应该在[FIRMessaging messaging].delegate = self;之前调用[FIRApp configure];

2：当您发布 AppDelegate.m 文件的完整代码时。因此缺少以下将令牌更新/发送到 Firebase 的方法。您将在此 UIApplication 的委托方法中收到一个 TOKEN，您必须为 Firebase 设置它（只需将此方法放入您的 AppDelegate.m 文件中）

- (void)application:(UIApplication *)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken{

    NSString *strDevicetoken = [[NSString alloc]initWithFormat:@"%@",[[[deviceToken description] stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"<>"]] stringByReplacingOccurrencesOfString:@" " withString:@""]];

    NSLog(@"Device Token = %@",strDevicetoken);
    [FIRMessaging messaging].APNSToken = deviceToken;
    //NSString *fcmToken = [FIRMessaging messaging].FCMToken;
    //NSLog(@"FCM registration token: %@", fcmToken);
}

现在您已成功在 Firebase 设置 APNS Token，您现在可以在 Firebase 订阅您想要的主题

【讨论】：