[iOS] Button CharacterSpacing Fix

src/Controls/src/Core/Button/Button.iOS.cs

@@ -439,6 +439,10 @@ private static void MapPadding(IButtonHandler handler, Button button)
 		public static void MapText(IButtonHandler handler, Button button)
 		{
 			handler.PlatformView?.UpdateText(button);
+
+			// Update all of the attributed text formatting properties
+			var fontManager = handler.GetRequiredService<IFontManager>();
+			handler.PlatformView?.UpdateAttributedTitle(fontManager, button);
 		}
 
 		internal static void MapBorderWidth(IButtonHandler handler, Button button)

src/Controls/tests/TestCases.HostApp/Issues/Issue18832.xaml

@@ -0,0 +1,12 @@
+<?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.Issue18832"
+             xmlns:ns="clr-namespace:Maui.Controls.Sample.Issues">
+    <VerticalStackLayout>
+        <Label Text="Button: "/>
+        <Button AutomationId="button" Text="Hello, World!" CharacterSpacing="10" FontSize="30" FontFamily="OpenSansRegular" TextColor="DarkBlue"/>
+        <Label Text="Label: "/>
+        <Label AutomationId="label" Text="Hello, World!" CharacterSpacing="10" FontSize="30" FontFamily="OpenSansRegular"/>
+    </VerticalStackLayout>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue18832.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, 18832, "[iOS] Button CharacterSpacing makes FontSize fixed and large", PlatformAffected.iOS)]
+	public partial class Issue18832 : ContentPage
+	{
+		public Issue18832()
+		{
+			InitializeComponent();
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue18832.cs

@@ -0,0 +1,26 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue18832 : _IssuesUITest
+	{
+		public override string Issue => "[iOS] Button CharacterSpacing makes FontSize fixed and large";
+
+		public Issue18832(TestDevice device) : base(device)
+		{
+		}
+
+		[Test]
+		[Category(UITestCategories.Button)]
+		public void SizesOfBothTextsShouldHaveTheSameAndCharacterSpacing()
+		{
+			_ = App.WaitForElement("button");
+
+			// The test passes if both "Hello, World!" texts are of the same size
+			// and have the same character spacing
+			VerifyScreenshot();
+		}
+	}
+}

src/Core/src/Handlers/Button/ButtonHandler.iOS.cs

@@ -98,7 +98,8 @@ public static void MapText(IButtonHandler handler, IText button)
 			handler.PlatformView?.UpdateText(button);
 
 			// Any text update requires that we update any attributed string formatting
-			MapFormatting(handler, button);
+			var fontManager = handler.GetRequiredService<IFontManager>();
+			handler.PlatformView?.UpdateAttributedTitle(fontManager, button);
 		}
 
 		public static void MapTextColor(IButtonHandler handler, ITextStyle button)
@@ -116,11 +117,17 @@ public static void MapTextColor(IButtonHandler handler, ITextStyle button)
 			{
 				handler.PlatformView?.UpdateTextColor(button);
 			}
+
+			var fontManager = handler.GetRequiredService<IFontManager>();
+			handler.PlatformView?.UpdateAttributedTitle(fontManager, button!);
 		}
 
 		public static void MapCharacterSpacing(IButtonHandler handler, ITextStyle button)
 		{
 			handler.PlatformView?.UpdateCharacterSpacing(button);
+
+			var fontManager = handler.GetRequiredService<IFontManager>();
+			handler.PlatformView?.UpdateAttributedTitle(fontManager, button);
 		}
 
 		public static void MapPadding(IButtonHandler handler, IButton button)
@@ -133,12 +140,14 @@ public static void MapFont(IButtonHandler handler, ITextStyle button)
 			var fontManager = handler.GetRequiredService<IFontManager>();
 
 			handler.PlatformView?.UpdateFont(button, fontManager);
+
+			handler.PlatformView?.UpdateAttributedTitle(fontManager, button);
 		}
 
 		public static void MapFormatting(IButtonHandler handler, IText button)
 		{
-			// Update all of the attributed text formatting properties
-			handler.PlatformView?.UpdateCharacterSpacing(button);
+			var fontManager = handler.GetRequiredService<IFontManager>();
+			handler.PlatformView?.UpdateAttributedTitle(fontManager, button);
 		}
 
 		public static void MapImageSource(IButtonHandler handler, IImage image) =>

src/Core/src/Platform/iOS/ButtonExtensions.cs

@@ -1,4 +1,5 @@
 using System;
+using Foundation;
 using UIKit;
 
 namespace Microsoft.Maui.Platform
@@ -112,5 +113,32 @@ internal static void UpdateContentEdgeInsets(this UIButton platformButton, Thick
 #pragma warning restore CA1422 // Validate platform compatibility
 #pragma warning restore CA1416
 		}
+
+		internal static void UpdateAttributedTitle(this UIButton platformButton, IFontManager fontManager, ITextStyle textStyle)
+		{
+			if(platformButton.CurrentTitle == null)
+			{
+				return;
+			}
+
+			// Any text update requires that we update any attributed string formatting
+			var uiFontAttribute = fontManager.GetFont(textStyle.Font, UIFont.ButtonFontSize);
+			var attributedString = new NSMutableAttributedString(new NSAttributedString(platformButton.CurrentTitle));
+
+			// Update font family & size
+			attributedString.AddAttribute(UIStringAttributeKey.Font, uiFontAttribute, new NSRange(0, attributedString.Length));
+
+			//Update UpdateCharacterSpacing
+			if (textStyle.CharacterSpacing != 0)
+			{
+				attributedString = attributedString.WithCharacterSpacing(textStyle.CharacterSpacing);
+			}
+
+			//Update Text Color
+			if (textStyle.TextColor != null)
+				attributedString = attributedString?.WithTextColor(textStyle.TextColor);
+
+			platformButton.SetAttributedTitle(attributedString, UIControlState.Normal);
+		}
 	}
 }