Question

我能够接收到消息，但仅显示在日志中。我想在屏幕顶部显示为通知。

这是我的代码： MainActivity.cs

static readonly string TAG = "MainActivity";
internal static readonly string CHANNEL_ID = "my_notification_channel";
internal static readonly int NOTIFICATION_ID = 100;
protected override void OnCreate(Bundle bundle)
{
            TabLayoutResource = Resource.Layout.Tabbar;
            ToolbarResource = Resource.Layout.Toolbar;

            base.OnCreate(bundle);
            UserDialogs.Init(this);
            CreateNotificationChannel();
            CrossMedia.Current.Initialize();
            Plugin.CurrentActivity.CrossCurrentActivity.Current.Activity = this;

            global::Xamarin.Forms.Forms.Init(this, bundle);
            LoadApplication(new App(FirebaseInstanceId.Instance.Token));
}

void CreateNotificationChannel()
        {
            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;
            }

            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);
        }
    }

在MyFirebaseMessagingService类中

[Service]
    [IntentFilter(new[] { "com.google.firebase.MESSAGING_EVENT" })]
    public class MyFirebaseMessagingService : FirebaseMessagingService
    {
        const string TAG = "MyFirebaseMsgService";
        public override void OnMessageReceived(RemoteMessage message)
        {
            Log.Debug(TAG, "From: " + message.From);
            var body = message.GetNotification().Body;
            Log.Debug(TAG, "Notification Message Body: " + body);
            SendNotification(body, message.Data);
        }

        void SendNotification(string messageBody, IDictionary<string, string> data)
        {
            var intent = new Intent(this, typeof(MainActivity));
            intent.AddFlags(ActivityFlags.ClearTop);
            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.ic_stat_ic_notification)
                                      .SetContentTitle("FCM Message")
                                      .SetContentText(messageBody)
                                      .SetAutoCancel(true)
                                      .SetContentIntent(pendingIntent);

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

我可以在以下位置收到消息：Log.Debug(TAG, "Notification Message Body: " + body);，它将在调用SendNotification函数之后，然后在此行中记录该消息的正文：

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

它将出现错误：Java.Lang.IllegalArgumentException: <Timeout exceeded getting exception details>

在哪里可以获取CHANNEL_ID和NOTIFICATION_ID的值？当前，它具有值：my_notification_channel和100分别与文档中的相同。这是我遇到此错误的原因吗？

请帮助。谢谢。

Answer 1

您在使用Notification时遇到了问题

var notificationBuilder = new NotificationCompat.Builder(this, MainActivity.CHANNEL_ID)
                                  .SetSmallIcon(Resource.Drawable.ic_stat_ic_notification) //you could not commen it
                                  .SetContentTitle("FCM Message")
                                  .SetContentText(messageBody)
                                  .SetAutoCancel(true)
                                  .SetContentIntent(pendingIntent);

SetSmallIcon 是必需参数，否则会生成错误

FCM前台通知Java.Lang.IllegalArgumentException错误

1 个答案: