Xamarin Forms 实现发送通知点击跳转

1. Ensure the you have set LaunchMode.SingleTop on your MainActivity:

LaunchMode.SingleTop

     [Activity(Label = "云销管家",
         Icon = "@mipmap/ic_launcher",
         Theme = "@style/MainTheme",
         LaunchMode = LaunchMode.SingleTop,
         ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
     public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity, IBDLocationListener
     {

In your MainActivity (the FormsAppCompatActivity subclass) add a OnNewIntent override:

OnNewIntent:

 protected override void OnNewIntent(Intent intent)
 {
     base.OnNewIntent(intent);
     NotificationClickedOn(intent);
 }

Now you can check the intent.Action / intent.HasExtra to determine if it is your notification that was send and thus process it. With Xamarin.Forms the easiest would be to use MessagingCenter to send a message that is subscribed to within your .NetStd/PCL Xamarin.Forms code base.

NotificationClickedOn:

         void NotificationClickedOn(Intent intent)
         {

             if (intent.Action == "LocalNotifierIntent1300" && intent.HasExtra("LocalNotification"))
             {
                 var notificationMessage = intent.Extras.GetString("LocalNotification");
                 var winnerToast = Toast.MakeText(this, $"{notificationMessage}.", ToastLength.Long);
                 winnerToast.SetGravity(Android.Views.GravityFlags.Center, , );
                 winnerToast.Show();
             }
         }

Send notification example:

 void SendNotifacation()
 {
     var title = "Winner, Winner, Chicken Dinner";
     var message = "You just won a million StackOverflow reputation points";

     var intent = new Intent(BaseContext, typeof(MainActivity));
     intent.SetAction("ASushiNotification");
     intent.PutExtra("MessageFromSushiHangover", message);
     var pending = PendingIntent.GetActivity(BaseContext, , intent, PendingIntentFlags.CancelCurrent);

     using (var notificationManager = NotificationManager.FromContext(BaseContext))
     {
         Notification notification;
         if (Android.OS.Build.VERSION.SdkInt < Android.OS.BuildVersionCodes.O)
         {
 #pragma warning disable CS0618 // Type or member is obsolete
             notification = new Notification.Builder(BaseContext)
                                                         .SetContentTitle(title)
                                                         .SetContentText(message)
                                                         .SetAutoCancel(true)
                                                         .SetSmallIcon(Resource.Drawable.icon)
                                                         .SetDefaults(NotificationDefaults.All)
                                                         .SetContentIntent(pending)
                                                         .Build();
 #pragma warning restore CS0618 // Type or member is obsolete
         }
         else
         {
             var myUrgentChannel = BaseContext.PackageName;
             const string channelName = "Messages from SushiHangover";

             NotificationChannel channel;
             channel = notificationManager.GetNotificationChannel(myUrgentChannel);
             if (channel == null)
             {
                 channel = new NotificationChannel(myUrgentChannel, channelName, NotificationImportance.High);
                 channel.EnableVibration(true);
                 channel.EnableLights(true);
                 channel.SetSound(
                     RingtoneManager.GetDefaultUri(RingtoneType.Notification),
                     new AudioAttributes.Builder().SetUsage(AudioUsageKind.Notification).Build()
                 );
                 channel.LockscreenVisibility = NotificationVisibility.Public;
                 notificationManager.CreateNotificationChannel(channel);
             }
             channel?.Dispose();

             notification = new Notification.Builder(BaseContext)
                                                         .SetChannelId(myUrgentChannel)
                                                         .SetContentTitle(title)
                                                         .SetContentText(message)
                                                         .SetAutoCancel(true)
                                                         .SetSmallIcon(Resource.Drawable.icon)
                                                         .SetContentIntent(pending)
                                                         .Build();
         }
         notificationManager.Notify(, notification);
         notification.Dispose();
     }
 }