(Windows) ImageButton contents now explicitly stretches

src/Controls/samples/Controls.Sample.UITests/Controls.Sample.UITests.csproj

@@ -45,6 +45,18 @@
     <MauiSplashScreen Include="Resources\Splash\splash.svg" Color="#FFFFFF" BaseSize="168,208" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Compile Update="Issues\Issue16918.xaml.cs">
+      <DependentUpon>Issue16918.xaml</DependentUpon>
+    </Compile>
+  </ItemGroup>
+
   <Import Project="$(MauiSrcDirectory)Maui.InTree.props" Condition=" '$(UseMaui)' != 'true' " />
 
+  <ItemGroup>
+    <MauiXaml Update="Issues\Issue16918.xaml">
+      <Generator>MSBuild:Compile</Generator>
+    </MauiXaml>
+  </ItemGroup>
+
 </Project>

src/Controls/samples/Controls.Sample.UITests/Issues/Issue16918.xaml

@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue16918"
+             xmlns:ns="clr-namespace:Maui.Controls.Sample.Issues">
+    <ScrollView>
+        <VerticalStackLayout
+            Spacing="25"
+            Padding="30,0"
+            VerticalOptions="Center">
+            <Label 
+                Text="Image (SVG 40x40):"
+                HorizontalOptions="Center" />
+            <Image 
+                Source="menu_entry_settings_40.png"
+                SemanticProperties.Description="Cute dot net bot waving hi to you!"
+                HeightRequest="40"
+                HorizontalOptions="Center" />
+
+            <Label 
+                Text="ImageButton (SVG 40x40):"
+                HorizontalOptions="Center" />
+            <ImageButton 
+                Source="menu_entry_settings_40.png"
+                SemanticProperties.Description="Cute dot net bot waving hi to you!"
+                HeightRequest="40"
+                BackgroundColor="Transparent"
+                HorizontalOptions="Center" />
+
+            <Label 
+                Text="Image (SVG 210x210):"
+                HorizontalOptions="Center" />
+            <Image 
+                Source="menu_entry_settings_210.png"
+                SemanticProperties.Description="Cute dot net bot waving hi to you!"
+                HeightRequest="40"
+                HorizontalOptions="Center" />
+
+            <Label 
+                Text="ImageButton (SVG 210x210):"
+                HorizontalOptions="Center" />
+            <ImageButton
+                Source="menu_entry_settings_210.png"
+                SemanticProperties.Description="Cute dot net bot waving hi to you!"
+                HeightRequest="40"
+                BackgroundColor="Transparent"
+                HorizontalOptions="Center" />
+        </VerticalStackLayout>
+    </ScrollView>
+</ContentPage>

src/Controls/samples/Controls.Sample.UITests/Issues/Issue16918.xaml.cs

@@ -0,0 +1,15 @@
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	[Issue(IssueTracker.Github, 16918, "ImageButton is not properly anti-aliased when scaled down", PlatformAffected.UWP)]
+	public partial class Issue16918 : ContentPage
+	{
+		public Issue16918()
+		{
+			InitializeComponent();
+		}
+	}
+}

src/Controls/tests/UITests/Tests/Issues/Issue16918.cs

@@ -0,0 +1,30 @@
+using Microsoft.Maui.Appium;
+using Microsoft.Maui.AppiumTests;
+using NUnit.Framework;
+
+namespace Controls.AppiumTests.Tests.Issues
+{
+	public class Issue16918 : _IssuesUITest
+	{
+		public Issue16918(TestDevice device)
+			: base(device)
+		{ }
+
+		public override string Issue => "Image buttons aliasing";
+
+		[Test]
+		public void Issue16918Test()
+		{
+			// https://github.com/dotnet/maui/issues/16918
+			UITestContext.IgnoreIfPlatforms(new[]
+			{
+				TestDevice.Mac,
+				TestDevice.Android,
+				TestDevice.iOS
+			});
+
+			App.WaitForElement("WaitForStubControl");
+			VerifyScreenshot();
+		}
+	}
+}

src/Core/src/Platform/Windows/ButtonExtensions.cs

@@ -161,36 +161,9 @@ public static void UpdateImageSource(this Button platformButton, WImageSource? n
 			{
 				nativeImage.Source = nativeImageSource;
 
-				if (nativeImageSource is not null)
-				{
-					// set the base size if we can
-					{
-						var imageSourceSize = nativeImageSource.GetImageSourceSize(platformButton);
-						nativeImage.Width = imageSourceSize.Width;
-						nativeImage.Height = imageSourceSize.Height;
-					}
-
-					// BitmapImage is a special case that has an event when the image is loaded
-					// when this happens, we want to resize the button
-					if (nativeImageSource is BitmapImage bitmapImage)
-					{
-						bitmapImage.ImageOpened += OnImageOpened;
-
-						void OnImageOpened(object sender, RoutedEventArgs e)
-						{
-							bitmapImage.ImageOpened -= OnImageOpened;
-
-							// Check if the image that just loaded is still the current image
-							var actualImageSource = sender as BitmapImage;
-
-							if (actualImageSource is not null && nativeImage.Source == actualImageSource)
-								nativeImage.Height = nativeImage.Width = Primitives.Dimension.Unset;
-
-							if (platformButton.Parent is FrameworkElement frameworkElement)
-								frameworkElement.InvalidateMeasure();
-						};
-					}
-				}
+				// Stretch to the size of the button
+				nativeImage.HorizontalAlignment = UI.Xaml.HorizontalAlignment.Stretch;
+				nativeImage.VerticalAlignment = UI.Xaml.VerticalAlignment.Stretch;
 
 				nativeImage.Visibility = nativeImageSource == null
 					? UI.Xaml.Visibility.Collapsed