Fix loaded so it fires on second subscription

src/Controls/src/Core/VisualElement/VisualElement.Standard.cs

@@ -8,13 +8,13 @@ public partial class VisualElement
 	{
 		partial void HandlePlatformUnloadedLoaded()
 		{
-			if (Window != null)
+			if (this.IsLoaded)
 			{
-				SendLoaded();
+				SendLoaded(false);
 			}
 			else
 			{
-				SendUnloaded();
+				SendUnloaded(false);
 			}
 		}
 	}

src/Controls/src/Core/VisualElement/VisualElement.cs

@@ -2146,19 +2146,19 @@ public event EventHandler? Loaded
 		{
 			add
 			{
-				bool watchingLoaded = _watchingPlatformLoaded;
+				bool loadedAlreadyFired = _isLoadedFired;
+
 				_loaded += value;
 				UpdatePlatformUnloadedLoadedWiring(Window);
 
-				// The point of this code, is to fire loaded if the element is already loaded.
-				//
-				// If this is the first time the user is subscribing to Loaded,
-				// UpdatePlatformUnloadedLoadedWiring will take care of firing Loaded.
-				// If we are already wired up to watch loaded, then we'll fire it off if we know this
-				// view is in a state where it's been determined that it's accurate to fire
-				// _isLoadedFired.
-				if (_isLoadedFired && watchingLoaded)
+				// The first time UpdatePlatformUnloadedLoadedWiring is called it will handle
+				// invoking _loaded
+				// This is only to make sure that new subscribers get invoked when the element is already loaded
+				// and a previous subscriber has already invoked the UpdatePlatformUnloadedLoadedWiring path
+				if (loadedAlreadyFired && _isLoadedFired)
+				{
 					value?.Invoke(this, EventArgs.Empty);
+				}
 
 			}
 			remove
@@ -2212,7 +2212,9 @@ void SendLoaded(bool updateWiring)
 			// unloaded is still correctly being watched for.
 
 			if (updateWiring)
+			{
 				UpdatePlatformUnloadedLoadedWiring(Window);
+			}
 		}
 
 		void SendUnloaded() => SendUnloaded(true);

src/Controls/tests/Core.UnitTests/PageLifeCycleTests.cs

@@ -287,6 +287,31 @@ public async Task LoadedUnLoadedEvents()
 			Assert.Equal(1, unLoadedCnt);
 		}
 
+		[Fact]
+		public async Task LoadedFiresOnSecondSubscription()
+		{
+			var previousPage = new LCPage();
+			var lcPage = new LCPage();
+			var navigationPage =
+				new TestNavigationPage(true, previousPage)
+					.AddToTestWindow();
+
+			await navigationPage.PushAsync(lcPage);
+
+			int loadedCnt = 0;
+			lcPage.Loaded += OnLoaded;
+			Assert.Equal(1, loadedCnt);
+
+			lcPage.Loaded -= OnLoaded;
+			lcPage.Loaded += OnLoaded;		
+			Assert.Equal(2, loadedCnt);
+
+			void OnLoaded(object sender, System.EventArgs e)
+			{
+				loadedCnt++;
+			}
+		}
+
 		[Fact]
 		public async Task LoadedFiresOnInitialSubscription()
 		{
@@ -299,6 +324,7 @@ public async Task LoadedFiresOnInitialSubscription()
 			await navigationPage.PushAsync(lcPage);
 
 			int loadedCnt = 0;
+			int secondLoadedSubscriberCnt = 0;
 			int unLoadedCnt = 0;
 
 			Assert.True(lcPage.IsLoaded);
@@ -309,21 +335,25 @@ public async Task LoadedFiresOnInitialSubscription()
 				loadedCnt++;
 			};
 
-			// Subscribing to loaded should fire the loaded
-			// event if the page is already loaded
+			Assert.Equal(1, loadedCnt);
+
+			// Subscribing to loaded a second time
+			// Should fire the event on the new subsciber;
 			lcPage.Loaded += (_, _) => 
 			{
-				loadedCnt++;
+				secondLoadedSubscriberCnt++;
 			};
 
 			lcPage.Unloaded += (_, _) => unLoadedCnt++;
 
-			Assert.Equal(2, loadedCnt);
+			Assert.Equal(1, loadedCnt);
+			Assert.Equal(1, secondLoadedSubscriberCnt);
 			Assert.Equal(0, unLoadedCnt);
 
 			await navigationPage.PopAsync();
 
-			Assert.Equal(2, loadedCnt);
+			Assert.Equal(1, loadedCnt);
+			Assert.Equal(1, secondLoadedSubscriberCnt);
 			Assert.Equal(1, unLoadedCnt);
 		}