如何使用 swift 3 通过 firebase 推送通知发送图像

任何人都可以帮我发送这样的通知：

我正在使用 Firebase 通知。当我发送通知时，我尝试将图像 URL 放入高级选项和键 1 的值中。图像 URL 显示在调试器中，但当我的设备中出现通知时，没有显示图像。

这是我的代码。

import UIKit
import UserNotifications
import Firebase
import FirebaseInstanceID
import FirebaseMessaging

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?
let gcmMessageIDKey = "gcm.message_id"

func application(_ application: UIApplication,
                 didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    // Register for remote notifications. This shows a permission dialog on first run, to
    // show the dialog at a more appropriate time move this registration accordingly.
    // [START register_for_notifications]
    if #available(iOS 10.0, *) {
        let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound]
        UNUserNotificationCenter.current().requestAuthorization(
            options: authOptions,
            completionHandler: {_, _ in })

        // For iOS 10 display notification (sent via APNS)
        UNUserNotificationCenter.current().delegate = self
        // For iOS 10 data message (sent via FCM)
        FIRMessaging.messaging().remoteMessageDelegate = self

    } else {
        let settings: UIUserNotificationSettings =
            UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
        application.registerUserNotificationSettings(settings)
    }

    application.registerForRemoteNotifications()

    // [END register_for_notifications]
    FIRApp.configure()

    // Add observer for InstanceID token refresh callback.
     NotificationCenter.default.addObserver(self,
                                           selector:  #selector(self.tokenRefreshNotification),
                                           name: .firInstanceIDTokenRefresh,
                                           object: nil)

 FIRDatabase.database().persistenceEnabled = true

    loggedInUser()
    return true
}

// [START receive_message]
func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {
    // If you are receiving a notification message while your app is in the background,
    // this callback will not be fired till the user taps on the notification launching the application.
    // TODO: Handle data of notification
    // Print message ID.
    if let messageID = userInfo[gcmMessageIDKey] {
        print("Message ID: \(messageID)")
    }

    // Print full message.
    print(userInfo)
 }

 func application(_ application: UIApplication,  didReceiveRemoteNotification userInfo: [AnyHashable: Any],
                 fetchCompletionHandler completionHandler: @escaping  (UIBackgroundFetchResult) -> Void) {
    // If you are receiving a notification message while your app is in the background,
    // this callback will not be fired till the user taps on the notification launching the application.
    // TODO: Handle data of notification
    // Print message ID.
    if let messageID = userInfo[gcmMessageIDKey] {
        print("Message ID: \(messageID)")
    }

    // Print full message.
    print(userInfo)

    completionHandler(UIBackgroundFetchResult.newData)
}
// [END receive_message]
// [START refresh_token]
func tokenRefreshNotification(_ notification: Notification) {
    if let refreshedToken = FIRInstanceID.instanceID().token() {
        print("InstanceID token: \(refreshedToken)")
    }

    // Connect to FCM since connection may have failed when attempted before having a token.
    connectToFcm()
}
// [END refresh_token]
// [START connect_to_fcm]
func connectToFcm() {
    // Won't connect since there is no token
    guard FIRInstanceID.instanceID().token() != nil else {
        return;
    }

    // Disconnect previous FCM connection if it exists.
    FIRMessaging.messaging().disconnect()

    FIRMessaging.messaging().connect { (error) in
        if error != nil {
            print("Unable to connect with FCM. \(error)")
        } else {
            print("Connected to FCM.")
        }
    }
}
// [END connect_to_fcm]
func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
    print("Unable to register for remote notifications: \(error.localizedDescription)")
  }

 // This function is added here only for debugging purposes, and can be removed if swizzling is enabled.
  // If swizzling is disabled then this function must be implemented so that the APNs token can be paired to
  // the InstanceID token.
  func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    print("APNs token retrieved: \(deviceToken)")

   // FIRInstanceID.instanceID().setAPNSToken(deviceToken, type: FIRInstanceIDAPNSTokenType.unknown)

    // With swizzling disabled you must set the APNs token here.
     FIRInstanceID.instanceID().setAPNSToken(deviceToken, type: FIRInstanceIDAPNSTokenType.sandbox)
}

// [START connect_on_active]
func applicationDidBecomeActive(_ application: UIApplication) {
    connectToFcm()
}
// [END connect_on_active]
// [START disconnect_from_fcm]
func applicationDidEnterBackground(_ application: UIApplication) {
    FIRMessaging.messaging().disconnect()
    print("Disconnected from FCM.")
}
// [END disconnect_from_fcm]
}

   // [START ios_10_message_handling]
 @available(iOS 10, *)
 extension AppDelegate : UNUserNotificationCenterDelegate {

// Receive displayed notifications for iOS 10 devices.
func userNotificationCenter(_ center: UNUserNotificationCenter,
                            willPresent notification: UNNotification,
                            withCompletionHandler completionHandler:   @escaping (UNNotificationPresentationOptions) -> Void) {
    let userInfo = notification.request.content.userInfo
    // Print message ID.
    if let messageID = userInfo[gcmMessageIDKey] {
        print("Message ID: \(messageID)")
    }

    // Print full message.
    print(userInfo)

    // Change this to your preferred presentation option
    completionHandler([])
 }

 func userNotificationCenter(_ center: UNUserNotificationCenter,
                            didReceive response:  UNNotificationResponse,
                            withCompletionHandler completionHandler: @escaping () -> Void) {
    let userInfo = response.notification.request.content.userInfo
    // Print message ID.
    if let messageID = userInfo[gcmMessageIDKey] {
        print("Message ID: \(messageID)")
    }

    // Print full message.
    print(userInfo)

    completionHandler()
  }
 }
  // [END ios_10_message_handling]
  // [START ios_10_data_message_handling]
 extension AppDelegate : FIRMessagingDelegate {
// Receive data message on iOS 10 devices while app is in the foreground.
func applicationReceivedRemoteMessage(_ remoteMessage: FIRMessagingRemoteMessage) {
    print(remoteMessage.appData)
}

func loggedInUser(){

    if FIRAuth.auth()!.currentUser != nil {

        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let root = storyboard.instantiateViewController(withIdentifier: "menu") as! UINavigationController
        self.window?.rootViewController = root
    }




 }


}