[Windows] Fixed Entry Editor placeholder Text CharacterSpacing

src/Controls/tests/TestCases.HostApp/Issues/Issue30071.cs

@@ -0,0 +1,57 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 30071, "Entry Editor Placeholder CharacterSpacing Property Not Working on Windows", PlatformAffected.UWP)]
+
+public class Issue30071 : ContentPage
+{
+	public Issue30071()
+	{
+		var label = new Label
+		{
+			Text = "Test passes if Entry and Editor Placeholder has character Spacing",
+			AutomationId = "label",
+			HorizontalOptions = LayoutOptions.Center,
+			VerticalOptions = LayoutOptions.Center,
+		};
+
+		var entry = new Entry
+		{
+			Placeholder = "Enter text here",
+			CharacterSpacing = 10,
+			AutomationId = "entry",
+			HorizontalOptions = LayoutOptions.Center,
+			VerticalOptions = LayoutOptions.Center,
+		};
+
+		var editor = new Editor
+		{
+			Placeholder = "Enter text here",
+			CharacterSpacing = 10,
+			HeightRequest = 100,
+			WidthRequest = 300,
+			HorizontalOptions = LayoutOptions.Center,
+			VerticalOptions = LayoutOptions.Center,
+		};
+
+		var button = new Button
+		{
+			Text = "Change Character Spacing to 20",
+			AutomationId = "button",
+			HorizontalOptions = LayoutOptions.Center,
+			Margin = 10
+		};
+
+		button.Clicked += (s, e) =>
+		{
+			entry.CharacterSpacing = 20;
+			editor.CharacterSpacing = 20;
+		};
+
+		Content = new StackLayout
+		{
+			Children = { label, entry, editor, button },
+			Spacing = 20,
+			Margin = new Thickness(20)
+		};
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue30071.cs

@@ -0,0 +1,33 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue30071 : _IssuesUITest
+{
+	public Issue30071(TestDevice device)
+		: base(device)
+	{
+	}
+
+	public override string Issue => "Entry Editor Placeholder CharacterSpacing Property Not Working on Windows";
+
+	[Test]
+	[Category(UITestCategories.Entry)]
+	public void Issue30071PlaceholderCharacterSpacingShouldApply()
+	{
+		App.WaitForElement("label");
+		VerifyScreenshot();
+	}
+
+	[Test]
+	[Category(UITestCategories.Entry)]
+	public void Issue30071PlaceholderCharacterSpacingShouldChange()
+	{
+		App.WaitForElement("entry");
+		App.WaitForElement("button");
+		App.Tap("button");
+		VerifyScreenshot();
+	}
+}

src/Core/src/Platform/Windows/TextBoxExtensions.cs

@@ -75,7 +75,27 @@ public static void UpdateTextColor(this TextBox textBox, ITextStyle textStyle)
 
 		public static void UpdateCharacterSpacing(this TextBox textBox, ITextStyle textStyle)
 		{
-			textBox.CharacterSpacing = textStyle.CharacterSpacing.ToEm();
+			var characterSpacing = textStyle.CharacterSpacing.ToEm();
+			textBox.CharacterSpacing = characterSpacing;
+
+			if (textBox.IsLoaded)
+			{
+				ApplyCharacterSpacingToPlaceholder(textBox, characterSpacing);
+			}
+			else
+			{
+				textBox.OnLoaded(() => ApplyCharacterSpacingToPlaceholder(textBox, characterSpacing));
+			}
+		}
+
+		static void ApplyCharacterSpacingToPlaceholder(this TextBox textBox, int characterSpacing)
+		{
+			var placeholderTextBlock = textBox.GetDescendantByName<TextBlock>("PlaceholderTextContentPresenter");
+			if (placeholderTextBlock is not null)
+			{
+				placeholderTextBlock.CharacterSpacing = characterSpacing;
+				placeholderTextBlock.RefreshThemeResources();
+			}
 		}
 
 		public static void UpdateReturnType(this TextBox textBox, ITextInput textInput)