当应用程序在后台Xamarin IOS FireBase中时推送通知

Question

我们正在为客户开发一个应用程序，推送通知已在Android（后台和前台）和iOS（前台）上完成。但是，当应用程序在后台运行时，从Firebase发送有效负载时，什么也不会触发。

[Export("messaging:didReceiveRemoteNotification")]
public override void DidReceiveRemoteNotification(
    UIApplication application,
    NSDictionary userInfo,
    Action<UIBackgroundFetchResult> completionHandler)
{
    displayNotification("notif1");
}

[Export("messaging:didReceiveMessage:")]
public void DidReceiveMessage(Messaging messaging, RemoteMessage remoteMessage)
{
    displayNotification("notif2");
}

{
  "validate_only": false,
  "message": {
    "data": {
      "action": "Create",
      "type": "A",
      "source": "WEB",
      "idDossier": "368",
      "idCartouche": "22953",
      "model": "{\"Id\":22953,\"...\":\"...\"}"
    },
    "notification": null,
    "android": null,
    "webpush": null,
    "apns": {
      "headers": {
        "apns-expiration": "0",
        "apns-priority": "10"
      },
      "payload": {
        "aps": {
          "alert": null,
          "badge": null,
          "sound": null,
          "content-available": 1,
          "mutable-content": 0,
          "category": null,
          "thread-id": null
        }
      }
    },
    "token": null,
    "topic": "d-368-u-77ffb0d907f04bfba8a0e3f35f7fd095",
    "condition": null
  }
}