推送通知不起作用Xcode 11.3.1

这是集成推送通知的过程，请逐步执行：

首次登录到您的Apple开发者帐户->标识符->单击您的应用程序标识符并启用推送通知。启用通知后，它将询问您CertificateSigningRequest.certSigningRequest，您需要打开钥匙串访问并打开单击证书助手->从证书颁发机构请求证书

创建该证书后，您需要在Apple帐户中添加该证书。并从那里下载development.cer和aps.cer证书。

下载这些证书后，只需单击两个证书，这将打开您的钥匙串访问。现在，左键单击那些证书并导出.p12证书，这将要求您为该证书生成密码。

现在打开您的Firebase帐户，然后转到设置->云消息传递->在此处添加production.p12和development.p12证书。

现在回到xcode转到应用程序目标->登录和功能->添加推送通知并添加后台模式，检查后台获取和远程通知。

现在进入代码，添加Pod并安装

pod 'Firebase/Analytics' 
pod 'Firebase/Messaging'

打开您的AppDelegate导入这些

import FirebaseAnalytics
import Firebase
import FirebaseMessaging

添加代表 MessagingDelegate

发起 let gcmMessageIDKey = "gcm.message_id"

在didFinishLaunchingWithOptions方法中添加这些

       FirebaseApp.configure()

        Messaging.messaging().delegate = self
        //Added push notification

        if #available(iOS 10.0, *) {
                 // For iOS 10 display notification (sent via APNS)
             UNUserNotificationCenter.current().delegate = self

             let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound]
             UNUserNotificationCenter.current().requestAuthorization(
                 options: authOptions,
                 completionHandler: {_, _ in })
         } else {
             let settings: UIUserNotificationSettings =
                 UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
             application.registerUserNotificationSettings(settings)
         }

         application.registerForRemoteNotifications()

         Messaging.messaging().isAutoInitEnabled = true

添加后，在应用程序委托中添加以下方法，您就可以接收推送通知了：

//Push Notifications

   func application(application: UIApplication,
                       didRegisterForRemoteNotificationsWithDeviceToken deviceToken: NSData) {
          Messaging.messaging().apnsToken = deviceToken as Data
      }
      func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {

          InstanceID.instanceID().instanceID { (result, error) in
              if let error = error {
                  print("Error fetching remote instance ID: \(error)")
              } else if let result = result {
                  print("Remote instance ID token: \(result.token)")
                  //  self.instanceIDTokenMessage.text  = "Remote InstanceID token: \(result.token)"
              }
          }

          print(userInfo)
      }

      func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any],
                       fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {

          if let messageID = userInfo[gcmMessageIDKey] {
              print("Message ID: \(messageID)")
          }

          print(userInfo)

          completionHandler(UIBackgroundFetchResult.newData)
      }

    func userNotificationCenter(_ center: UNUserNotificationCenter,
                                   willPresent notification: UNNotification,
                                   withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
           let userInfo = notification.request.content.userInfo

           if let messageID = userInfo[gcmMessageIDKey] {
               print("Message ID: \(messageID)")
           }

           completionHandler([])
       }

       func userNotificationCenter(_ center: UNUserNotificationCenter,
                                   didReceive response: UNNotificationResponse,
                                   withCompletionHandler completionHandler: @escaping () -> Void) {
           let userInfo = response.notification.request.content.userInfo

           if let messageID = userInfo[gcmMessageIDKey] {
               print("Message ID: \(messageID)")
           }

           print(userInfo)

           completionHandler()
       }


       func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String) {
           print("Firebase registration token: \(fcmToken)")
           let dataDict:[String: String] = ["token": fcmToken]


           NotificationCenter.default.post(name: Notification.Name("FCMToken"), object: nil, userInfo: dataDict)

           UserDefaults.standard.set(fcmToken, forKey: "FCMToken")
           UserDefaults.standard.synchronize()

       }

       func messaging(_ messaging: Messaging, did remoteMessage: MessagingRemoteMessage) {
           print("Received data message: \(remoteMessage.appData)")
       }

       func messaging(_ messaging: Messaging, didReceive remoteMessage: MessagingRemoteMessage) {
           print("Received data message: \(remoteMessage.appData)")
       }

       func application(_ application: UIApplication,
                        didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
           Messaging.messaging().apnsToken = deviceToken as Data

       }

       func messaging(_ messaging: Messaging, didRefreshRegistrationToken fcmToken: String) {
           print("Firebase registration token: \(fcmToken)")

           let dataDict:[String: String] = ["token": fcmToken]



       }