Just trigger SizeChanged when Window size changes

src/Controls/src/Core/Element/Element.cs

@@ -567,11 +567,17 @@ protected virtual void OnParentSet()
 
 		/// <summary>Method that is called when a bound property is changed.</summary>
 		/// <param name="propertyName">The name of the bound property that changed.</param>
-		protected override void OnPropertyChanged([CallerMemberName] string propertyName = null)
+		protected override void OnPropertyChanged([CallerMemberName] string propertyName = null) =>
+			OnPropertyChanged(propertyName, true);
+
+		internal void OnPropertyChanged(string propertyName = null, bool propagateToHandler = true)
 		{
 			base.OnPropertyChanged(propertyName);
 
-			Handler?.UpdateValue(propertyName);
+			if (propagateToHandler)
+			{
+				Handler?.UpdateValue(propertyName);
+			}
 
 			if (_effects?.Count > 0)
 			{
@@ -583,6 +589,7 @@ protected override void OnPropertyChanged([CallerMemberName] string propertyName
 			}
 		}
 
+
 		internal IEnumerable<Element> Descendants() =>
 			Descendants<Element>();
 

src/Controls/src/Core/Window/Window.cs

@@ -9,6 +9,7 @@
 using Microsoft.Maui.Controls.Internals;
 using Microsoft.Maui.Controls.Platform;
 using Microsoft.Maui.Graphics;
+using Microsoft.Maui.Layouts;
 
 namespace Microsoft.Maui.Controls
 {
@@ -229,10 +230,13 @@ void IWindow.FrameChanged(Rect frame)
 			{
 				SetPropertyChanged(XProperty, nameof(X), x, frame.X);
 				SetPropertyChanged(YProperty, nameof(Y), y, frame.Y);
-				SetPropertyChanged(WidthProperty, nameof(Width), width, frame.Width);
-				SetPropertyChanged(HeightProperty, nameof(Height), height, frame.Height);
 
-				SizeChanged?.Invoke(this, EventArgs.Empty);
+				if (width != frame.Width || height != frame.Height)
+				{
+					SetPropertyChanged(WidthProperty, nameof(Width), width, frame.Width, false);
+					SetPropertyChanged(HeightProperty, nameof(Height), height, frame.Height, false);
+					SizeChanged?.Invoke(this, EventArgs.Empty);
+				}
 			}
 
 			[MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -246,12 +250,12 @@ void SetPropertyChanging(BindableProperty property, string name, double oldValue
 			}
 
 			[MethodImpl(MethodImplOptions.AggressiveInlining)]
-			void SetPropertyChanged(BindableProperty property, string name, double oldValue, double newValue)
+			void SetPropertyChanged(BindableProperty property, string name, double oldValue, double newValue, bool shouldPropagateToHandler = true)
 			{
 				if (oldValue == newValue)
 					return;
 
-				OnPropertyChanged(name);
+				OnPropertyChanged(name, shouldPropagateToHandler);
 				property.PropertyChanged?.Invoke(this, oldValue, newValue);
 			}
 		}

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

@@ -449,6 +449,20 @@ public void SettingCoreFrameOnlyFiresEventOnce()
 			Assert.Equal(new[] { "X", "Y", "Width", "Height" }, changedProperties);
 		}
 
+		[Fact]
+		public void MovingWindowDoNotTriggerSizeChanged()
+		{
+			var sizeChangedCount = 0;
+
+			var window = new TestWindow();
+			window.SizeChanged += (sender, e) => sizeChangedCount++;
+
+			((IWindow)window).FrameChanged(new Rect(100, 200, 300, 400));
+			((IWindow)window).FrameChanged(new Rect(200, 300, 300, 400));
+
+			Assert.Equal(1, sizeChangedCount);
+		}
+
 		[Fact]
 		public void SettingSameCoreFrameDoesNothing()
 		{
@@ -486,7 +500,7 @@ public void UpdatingSingleCoordinateOnlyFiresSinglePropertyAndFrameEvent()
 
 			((IWindow)window).FrameChanged(new Rect(100, 250, 300, 400));
 
-			Assert.Equal(1, sizeChangedCount);
+			Assert.Equal(0, sizeChangedCount);
 			Assert.Equal(new[] { "Y" }, changingProperties);
 			Assert.Equal(new[] { "Y" }, changedProperties);
 		}