Question

我正在编写一个基于Xamarin.forms的应用程序，该应用程序当前正在android平台上运行。这是我第一次需要使用推送通知。我遵循了Microsoft（https://docs.microsoft.com/de-de/xamarin/android/data-cloud/google-messaging/remote-notifications-with-fcm?tabs=vswin）“）的指南来实施通知。

目标android版本是8.1 API27。该应用程序在具有Android 8.1的Samsung选项卡active 2上运行。

我已按照教程中的说明配置了该应用程序。我通过定义的通道推送消息，并且该通道已在应用程序中订阅。消息由服务器推送，服务器触发对FCM api的其余调用。第一天，我做了一些测试，传输效果非常好，我会说（几乎）可靠。

第二天，我实现了其他一些功能，并希望再次测试推送通知。然后：我很困惑，大多数邮件没有发送或很晚。我不确定是否所有消息都已发送，可能丢失了一些消息。

对我来说，FCM服务是一个很大的黑匣子，我可以在其中委派一些工作，然后我希望希望消息能够被传输。我现在很困惑。

我在此处粘贴了一些代码，但这几乎是您在本教程中可以找到的：

我的问题：我能做什么？是否可以从FCM中获取更多信息，我的消息当前正在做什么？还是代码有问题？

这在mainActivity中运行：

if (this.IsPlayServicesAvailable())
        {
            // Creates a notification channel
            this.CreateNotificationChannel();

            //Console.WriteLine("InstanceID token: " + FirebaseInstanceId.Instance.Token);


            // Subscribe to notification token
            FirebaseMessaging.Instance.SubscribeToTopic("channel");



            Log.Debug(TAG, "Subscribed to remote notifications");
}

这检查是否可以创建并创建通道：（在mainActivity中调用）

private void CreateNotificationChannel()
    {
        // The app is not running on Android 8.0 or higher
        if (Build.VERSION.SdkInt < BuildVersionCodes.O)
        {
            // Notification channels are new in API 26 (and not a part of the
            // support library). There is no need to create a notification
            // channel on older versions of Android.
            return;
        }

        // Create a notification channel for publishing notifications
        var channel = new NotificationChannel(CHANNEL_ID, "FCM Notifications", NotificationImportance.Default)
        {
            Description = "Firebase Cloud Messages appear in this channel"
        };

        var notificationManager = (NotificationManager)GetSystemService(Android.Content.Context.NotificationService);
        notificationManager.CreateNotificationChannel(channel);
}

这将检查playServices是否可用：（也称为mainActivity）

public bool IsPlayServicesAvailable()
    {
        int resultCode = GoogleApiAvailability.Instance.IsGooglePlayServicesAvailable(this);
        if (resultCode != ConnectionResult.Success)
        {
            if (GoogleApiAvailability.Instance.IsUserResolvableError(resultCode))
            {
                Log.Debug(TAG, GoogleApiAvailability.Instance.GetErrorString(resultCode));
            }
            else
            {
                Log.Debug(TAG, "This device has no compatible Google Play services APK - Download an APK from the Google Play Store or to enable it in the device's system settings!");
                Finish();
            }
            return false;
        }
        else
        {
            Log.Debug(TAG, "Google Play Services are available.");
            return true;
        }
    }

最后一个被删除的是用于处理通知并通知用户的服务：

[Service]
[IntentFilter(new[] { "com.google.firebase.MESSAGING_EVENT" })]
public class CustomFirebaseMessagingService : FirebaseMessagingService
{
    // Logging Tag
    private static readonly string TAG = "CustomFirebaseMessagingService";

    /* Handles data messages and notifications messages if the app is in foreground. 
     * 
     * Apps only have 10 seconds in which to handle an incoming Firebase Cloud Message. 
     * Any work that takes longer than this should be scheduled for background execution using a library such as the 'Android Job Scheduler' or the 'Firebase Job Dispatcher'.
     * 
     */
    public override void OnMessageReceived(RemoteMessage message)
    {
        Log.Debug(TAG, "Message from: " + message.From);

        // If the message data payload is not empty, display a notification
        if (message.Data.Count > 0)
        {
            Log.Debug(TAG, "Data Payload: " + message.Data.ToString());
            this.SendNotification(message.Data);
        }
    }

    // Converts the incoming FCM message into a local notification
    private void SendNotification(IDictionary<string, string> data)
    {
        Console.WriteLine("Push Message received");

        var intent = new Intent(this, typeof(MainActivity));
        intent.AddFlags(ActivityFlags.ClearTop);

        if (data.TryGetValue("message", out string message))
        {
            foreach (var key in data.Keys)
            {
                intent.PutExtra(key, data[key]);
            }

            var pendingIntent = PendingIntent.GetActivity(this, MainActivity.NOTIFICATION_ID, intent, PendingIntentFlags.OneShot);


            var notificationBuilder = new NotificationCompat.Builder(this, MainActivity.CHANNEL_ID)
                                      .SetSmallIcon(Resource.Drawable.NotificationIcon)
                                      .SetContentTitle("TITEL")
                                      .SetContentText(message)
                                      .SetAutoCancel(true)
                                      .SetContentIntent(pendingIntent);

            var notificationManager = NotificationManagerCompat.From(this);
            notificationManager.Notify(MainActivity.NOTIFICATION_ID, notificationBuilder.Build());


        }
    }
}

Xamarin.Forms推送通知的传输非常不可靠（无论是否迟到）

0 个答案: