ios - 应用程序在后台时不显示推送通知

Question

我正在尝试在我的 IOS 应用程序中实现 Firebase 推送通知，但无法弄清楚当应用程序处于后台时如何接收通知。

我使用 print 来显示通知，但它只在应用程序打开时打印通知。如果我在应用程序处于后台时发送通知，什么也不会发生，但消息会在我重新打开应用程序时立即打印出来。

下面是我的 AppDelegate 代码

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    registerForPushNotifications(application)
    FIRApp.configure()

    // Add observer for InstanceID token refresh callback.
    NSNotificationCenter
        .defaultCenter()
        .addObserver(self, selector: #selector(AppDelegate.tokenRefreshNotificaiton),
                     name: kFIRInstanceIDTokenRefreshNotification, object: nil)

    // Override point for customization after application launch.
    return true
}

func registerForPushNotifications(application: UIApplication) {
    let settings: UIUserNotificationSettings =
        UIUserNotificationSettings(forTypes: [.Alert, .Badge, .Sound], categories: nil)
    application.registerUserNotificationSettings(settings)
    application.registerForRemoteNotifications()
}


func application(application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject], fetchCompletionHandler completionHandler: (UIBackgroundFetchResult) -> Void) {
    sendNotification();

    print("===== didReceiveRemoteNotification ===== %@", userInfo)
}




func tokenRefreshNotificaiton(notification: NSNotification) {
    let refreshedToken = FIRInstanceID.instanceID().token()!
    print("InstanceID token: \(refreshedToken)")
    connectToFcm()
}

func connectToFcm() {
    FIRMessaging.messaging().connectWithCompletion { (error) in
        if (error != nil) {
            print("Unable to connect with FCM. \(error)")
        } else {
            print("Connected to FCM.")
        }
    }
}
func sendNotification() {
    let notification = UILocalNotification()
    let dict:NSDictionary = ["ID" : "your ID goes here"]
    notification.userInfo = dict as! [String : String]
    notification.alertBody = "title"
    notification.alertAction = "Open"
    notification.fireDate = NSDate()
    UIApplication.sharedApplication().scheduleLocalNotification(notification)


}


}

我也已经添加到我的 info.plist

<key>FirebaseAppDelegateProxyEnabled</key>
<false/>
<key>UIBackgroundModes</key>
<array>
    <string>remote-notification</string>
</array>

这是我发送的消息的格式

{
  "to" : "",
  "notification" : {
  "body" : "",
  "title" : "",
},
  "content_available": true,
  "priority": "high"
}

Answer 1

当您的应用程序关闭时，您无法接收推送通知数据。您应该将消息存储到服务器，而不是用户从那里访问消息