Fix Changing Location on a Pin does nothing

src/Controls/samples/Controls.Sample/Pages/Controls/MapsGalleries/MapPinsGallery.xaml

@@ -15,6 +15,9 @@
                 Text="Add Pin" 
                 Clicked="OnAddPinClicked" />
             <Button 
+                Text="Move Pin"
+                Clicked="OnMovePinClicked"/>
+            <Button
                 Text="Remove Pin"
                 Clicked="OnRemovePinClicked" />
             <Button 

src/Controls/samples/Controls.Sample/Pages/Controls/MapsGalleries/MapPinsGallery.xaml.cs

@@ -1,13 +1,15 @@
 using System;
 using Microsoft.Maui.Controls.Maps;
 using Microsoft.Maui.Controls.Xaml;
+using Microsoft.Maui.Maps;
 using Position = Microsoft.Maui.Devices.Sensors.Location;
 
 namespace Maui.Controls.Sample.Pages.MapsGalleries
 {
 	[XamlCompilation(XamlCompilationOptions.Compile)]
 	public partial class MapPinsGallery
 	{
+		const double DefaultMapRadiusKm = 5.0;
 		readonly Random _locationRandomSeed = new();
 		int _locationIncrement = 0;
 
@@ -81,6 +83,11 @@ void OnAddPinClicked(object sender, EventArgs e)
 			AddPin();
 		}
 
+		void OnMovePinClicked(object sender, EventArgs e)
+		{
+			MovePin();
+		}
+
 		void OnRemovePinClicked(object sender, EventArgs e)
 		{
 			if (pinsMap.Pins.Count > 0)
@@ -100,13 +107,34 @@ void OnAdd10PinsClicked(object sender, EventArgs e)
 
 		void AddPin()
 		{
-			pinsMap.Pins.Add(new Pin()
+			var randomLocation = GetRandomLocation();
+			var pin = new Pin
 			{
 				Label = $"Location {_locationIncrement++}",
-				Location = _randomLocations[_locationRandomSeed.Next(0, _randomLocations.Length)],
-			});
+				Location = randomLocation,
+			};
+			pinsMap.Pins.Add(pin);
+			MoveMapTo(randomLocation);
+		}
+
+		void MovePin()
+		{
+			if (pinsMap.Pins.Count == 0)
+			{
+				return;
+			}
+
+			var randomLocation = GetRandomLocation();
+			pinsMap.Pins[0].Location = randomLocation;
+			MoveMapTo(randomLocation);
 		}
 
+		Position GetRandomLocation() =>
+			_randomLocations[_locationRandomSeed.Next(_randomLocations.Length)];
+
+		void MoveMapTo(Position location) =>
+			pinsMap.MoveToRegion(MapSpan.FromCenterAndRadius(location, Distance.FromKilometers(DefaultMapRadiusKm)));
+
 		void OnMapClicked(object sender, MapClickedEventArgs e)
 		{
 			DisplayAlertAsync("Map", $"Map {e.Location.Latitude}, {e.Location.Longitude} clicked.", "Ok");

src/Core/maps/src/Handlers/Map/MapHandler.Android.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.Linq;
 using System.Threading.Tasks;
 using Android.Gms.Common.Apis;
@@ -56,6 +57,8 @@ protected override void ConnectHandler(MapView platformView)
 
 		protected override void DisconnectHandler(MapView platformView)
 		{
+			DisconnectPins();
+
 			base.DisconnectHandler(platformView);
 			platformView.LayoutChange -= MapViewLayoutChange;
 
@@ -260,10 +263,14 @@ public static void MapPins(IMapHandler handler, IMap map)
 		{
 			if (handler is MapHandler mapHandler)
 			{
+				mapHandler.DisconnectPins();
+
 				if (mapHandler._markers != null)
 				{
 					for (int i = 0; i < mapHandler._markers.Count; i++)
+					{
 						mapHandler._markers[i].Remove();
+					}
 
 					mapHandler._markers = null;
 				}
@@ -419,8 +426,7 @@ void AddPins(IList pins)
 			if (Map == null || MauiContext == null)
 				return;
 
-			if (_markers == null)
-				_markers = new List<Marker>();
+			_markers ??= new List<Marker>();
 
 			foreach (var p in pins)
 			{
@@ -430,20 +436,79 @@ void AddPins(IList pins)
 				var pinHandler = pin.ToHandler(MauiContext);
 				if (pinHandler is IMapPinHandler iMapPinHandler)
 				{
-					marker = Map.AddMarker(iMapPinHandler.PlatformView);
-					if (marker == null)
-					{
-						throw new System.Exception("Map.AddMarker returned null");
-					}
+					marker = Map.AddMarker(iMapPinHandler.PlatformView) ?? throw new System.Exception("Map.AddMarker returned null");
 					// associate pin with marker for later lookup in event handlers
 					pin.MarkerId = marker.Id;
 					_markers.Add(marker!);
 				}
 
+				if (pin is INotifyPropertyChanged observable)
+				{
+					observable.PropertyChanged += PinOnPropertyChanged;
+				}
 			}
 			_pins = null;
 		}
 
+		void PinOnPropertyChanged(object? sender, PropertyChangedEventArgs e)
+		{
+			if (sender is not IMapPin pin || _markers == null)
+			{
+				return;
+			}
+
+			Marker? marker = null;
+			if (pin.MarkerId is string markerId)
+			{
+				for (int i = 0; i < _markers.Count; i++)
+				{
+					if (_markers[i].Id == markerId)
+					{
+						marker = _markers[i];
+						break;
+					}
+				}
+			}
+
+			if (marker is null)
+			{
+				return;
+			}
+
+			switch (e.PropertyName)
+			{
+				case nameof(IMapPin.Location):
+					if (pin.Location != null)
+					{
+						marker.Position = new LatLng(pin.Location.Latitude, pin.Location.Longitude);
+					}
+
+					break;
+				case nameof(IMapPin.Label):
+					marker.Title = pin.Label;
+					break;
+				case nameof(IMapPin.Address):
+					marker.Snippet = pin.Address;
+					break;
+			}
+		}
+
+		void DisconnectPins()
+		{
+			if (VirtualView == null)
+				return;
+
+			for (int i = 0; i < VirtualView.Pins.Count; i++)
+			{
+				var pin = VirtualView.Pins[i];
+				if (pin is INotifyPropertyChanged observable)
+				{
+					observable.PropertyChanged -= PinOnPropertyChanged;
+				}
+				pin?.Handler?.DisconnectHandler();
+			}
+		}
+
 		protected IMapPin? GetPinForMarker(Marker marker)
 		{
 			IMapPin? targetPin = null;
@@ -618,4 +683,4 @@ protected override void Dispose(bool disposing)
 		}
 	}
 
-}
+}

src/Core/maps/src/Handlers/MapPin/MapPinHandler.Android.cs

@@ -1,4 +1,4 @@
-using Android.Gms.Maps;
+using Android.Gms.Maps;
 using Android.Gms.Maps.Model;
 using Microsoft.Maui.Handlers;
 
@@ -10,8 +10,10 @@ public partial class MapPinHandler : ElementHandler<IMapPin, MarkerOptions>
 
 		public static void MapLocation(IMapPinHandler handler, IMapPin mapPin)
 		{
-			if (mapPin.Location != null)
+			if (mapPin.Location is not null)
+			{
 				handler.PlatformView.SetPosition(new LatLng(mapPin.Location.Latitude, mapPin.Location.Longitude));
+			}
 		}
 
 		public static void MapLabel(IMapPinHandler handler, IMapPin mapPin)

src/Core/maps/src/PublicAPI/net-android/PublicAPI.Unshipped.txt

@@ -1 +1 @@
-#nullable enable
+#nullable enable