Question

我在Oreo设备上遇到问题，通知发送到客户端时，通知只是根本不显示在平视显示器上。我可以确保在背景中接收到它们，因为我创建了自定义振动效果OnMessageReceived，并且可以正常工作，但是在Android HUD中仍然没有显示任何内容。

此外，我注意到另一篇文章说，当强制关闭Visual Studio时，它会终止通知服务。的确如此，因为它也杀死了我的振动效果，但是在加载应用程序一面后，我可以从设备启动并触发我的自定义效果。

我相信我正在做的是1，将标签注册到Azure-FCM服务。第二，我说的是注册我的API端点以及允许的模板。我认为我注册的有效负载模板有问题，以及我要发送的有效载荷

请参阅下文。

Web API that generates Android payload
private string GetAndroidAlertJson(int? fromId, int notificationType, string message)
    {
        return new JObject(


           new JProperty("data",
               new JObject(
                   new JProperty("notification",

                       new JObject(
                           new JProperty("badge", 1),
                           new JProperty("body", message),
                           new JProperty("title", "wazzup?!"),
                           new JProperty("priority", "high")
                        )
                    ),
                   new JProperty("type_id", notificationType),
                   new JProperty("user", fromId != null ? fromId.ToString() : ""),
                   new JProperty("message", message)
                )
           )
       ).ToString();
    }

Xamarin.Android

//NotificationBuilder
return new NotificationCompat.Builder(ApplicationContext, PRIMARY_CHANNEL)
                 .SetContentTitle(title)
                 .SetContentText(body)
                 .SetSmallIcon(SmallIcon)
                 .SetPriority(2)
                 .SetVibrate(new long[0])
                 .SetAutoCancel(true);
//In MainActivity
public NotificationHelper(Context context) : base(context)
    {
        var chan1 = new NotificationChannel(PRIMARY_CHANNEL,
                PRIMARY_CHANNEL, NotificationImportance.Max);
        chan1.LightColor = 2;
        chan1.LockscreenVisibility = NotificationVisibility.Public;
        Manager.CreateNotificationChannel(chan1);
    }
public NotificationCompat.Builder GetNotification1(String title, String body)
    {
        return new NotificationCompat.Builder(ApplicationContext, PRIMARY_CHANNEL)
                 .SetContentTitle(title)
                 .SetContentText(body)
                 .SetSmallIcon(SmallIcon)
                 .SetPriority(2)
                 .SetVibrate(new long[0])
                 .SetAutoCancel(true);
    }
 FCMService
 [Service]
[IntentFilter(new[] { "com.google.firebase.MESSAGING_EVENT" })]
public class FCMMessagingService : FirebaseMessagingService
{//Foreground Only
    const string TAG = "MyFirebaseMsgService";
    public override void OnMessageReceived(RemoteMessage message)
    {
        if (Debugger.IsAttached)
            Debugger.Break();
        CustomNotificationEffect();
        try
        {
            if (message.Data.Count > 0)
            {
                var type_id = Convert.ToInt32(RetreiveNotification("type_id"));
                var body = RetreiveNotification("message");
                MainActivity.SendNotification(type_id, body);
            }
        }
        catch (Exception e)
        {
            //Was NotificationType null? this should never be null anyways
        }
        string RetreiveNotification(string key)
        {
            string value = String.Empty;
            message.Data.TryGetValue(key, out value);
            return value;
        }
    }
[Service]
[IntentFilter(new[] { "com.google.firebase.INSTANCE_ID_EVENT" })]
public class FCMInstanceIDService : FirebaseInstanceIdService
{
    const string TAG = "MyFirebaseIIDService";
    public static string ProfilePushTag;
    public async override void OnTokenRefresh()
    {
        var refreshedToken = FirebaseInstanceId.Instance.Token;
        Console.WriteLine("Token Received!: " + refreshedToken);
        await SendRegistrationToServer(refreshedToken);
    }
    public async Task SendRegistrationToServer(string token)
    {
        //We will have to send our token to the server here
        //

        string templateBodyFCM =
            "{" +
            "\"notification\" : {" +
            "\"body\" : \"$(messageParam)\"," +
            "\"title\" : \"Xamarin U\"," +
            "\"icon\" : \"myicon\" }}";
        var templates = new JObject();
        //templateBodyFCM = "Pyx";
        templates["genericMessage"] = new JObject
        {
            { "body", templateBodyFCM}
        };


        try
        {

            var tags = new List<string>();
            if (!String.IsNullOrWhiteSpace(ProfilePushTag))
            {
                // Register with Notification Hubs
                var hub = new NotificationHub("HUB-NAME",
                                      "AZURE-ENDPOINT"
                                      , this);
                tags.Add(ProfilePushTag);
                var regID = hub.Register(token, tags.ToArray()).RegistrationId;



                var hub2 = new MobileServiceClient("https://MyAPI");
                await hub2.GetPush().RegisterAsync(token, templates);
            }
        }
        catch (Exception e)
        {

        }
    }

Answer 1

在 Android O 中，必须在Notification Builder中使用频道以下是应如何使用的示例代码：

public NotificationCompat.Builder GetNotification1(String title, String body) {
 var mynotif = new Notification.Builder(ApplicationContext)
  .SetContentTitle(title)
  .SetContentText(body)
  .SetSmallIcon(SmallIcon)
  .SetPriority(2)
  .SetVibrate(new long[0])
  .SetAutoCancel(true);
 if (Build.VERSION.SdkInt >= BuildVersionCodes.O) {
  mynotif.SetChannelId(PRIMARY_CHANNEL);
 }

}

Answer 2

如果查看我的Web API，所有内容都包装在“数据”类型中。根据本文How to handle notification when app in background in Firebase，“数据”类型将不会显示在HUD中，但会显示“通知”类型。删除此属性可以解决此问题，并且现在显示在HUD中。

Xamarin.Android FCM通知在应用关闭/后台运行时未显示在HUD中

2 个答案: