[Windows] Fixed runtime update issue for SearchBar PlaceholderColor and BackgroundColor (#29965)

* Fixed SearchBar color issues

* Added test sample

* Added Windows and Mac snapshots

Author: Tamilarasan-Paranthaman

src/Controls/tests/TestCases.Android.Tests/snapshots/android/VerifySearchBarPlaceholderAndBackgroundColor.png

@@ -0,0 +1,38 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 29962, "[Windows] SearchBar PlaceHolder and Background Color should update properly at runtime", PlatformAffected.UWP)]
+public class Issue29962 : ContentPage
+{
+	public Issue29962()
+	{
+		var searchBar = new SearchBar
+		{
+			Placeholder = "Search here...",
+			Margin = new Thickness(0, 30),
+			BackgroundColor = Colors.Black,
+			PlaceholderColor = Colors.Yellow,
+			HeightRequest = 50,
+		};
+		var button = new Button
+		{
+			Text = "Change PlaceHolder and Background Color",
+			VerticalOptions = LayoutOptions.Center,
+			HorizontalOptions = LayoutOptions.Center,
+			AutomationId = "ColorChangeButton"
+		};
+		button.Clicked += (sender, e) =>
+		{
+			searchBar.BackgroundColor = Colors.YellowGreen;
+			searchBar.PlaceholderColor = Colors.Red;
+		};
+
+		Content = new StackLayout
+		{
+			Children =
+			{
+				searchBar,
+				button
+			}
+		};
+	}
+}

src/Controls/tests/TestCases.HostApp/Issues/Issue29962.cs

@@ -0,0 +1,23 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue29962 : _IssuesUITest
+{
+	public override string Issue => "[Windows] SearchBar PlaceHolder and Background Color should update properly at runtime";
+
+	public Issue29962(TestDevice device)
+	: base(device)
+	{ }
+
+	[Test]
+	[Category(UITestCategories.SearchBar)]
+	public void VerifySearchBarPlaceholderAndBackgroundColor()
+	{
+		App.WaitForElement("ColorChangeButton");
+		App.Tap("ColorChangeButton");
+		VerifyScreenshot();
+	}
+}

src/Controls/tests/TestCases.Mac.Tests/snapshots/mac/VerifySearchBarPlaceholderAndBackgroundColor.png

@@ -7,7 +7,7 @@ namespace Microsoft.Maui.Platform
 {
 	public static class SearchBarExtensions
 	{
-		private static readonly string[] _backgroundColorKeys =
+		static readonly string[] _backgroundColorKeys =
 		{
 			"TextControlBackground",
 			"TextControlBackgroundPointerOver",
@@ -17,7 +17,7 @@ public static class SearchBarExtensions
 
 		public static void UpdateBackground(this AutoSuggestBox platformControl, ISearchBar searchBar)
 		{
-			UpdateColors(platformControl.Resources, _backgroundColorKeys, searchBar.Background?.ToPlatform());
+			UpdateColors(platformControl, platformControl.Resources, _backgroundColorKeys, searchBar.Background?.ToPlatform());
 		}
 
 		public static void UpdateIsEnabled(this AutoSuggestBox platformControl, ISearchBar searchBar)
@@ -35,7 +35,7 @@ public static void UpdatePlaceholder(this AutoSuggestBox platformControl, ISearc
 			platformControl.PlaceholderText = searchBar.Placeholder ?? string.Empty;
 		}
 
-		private static readonly string[] _placeholderForegroundColorKeys =
+		static readonly string[] _placeholderForegroundColorKeys =
 		{
 			"TextControlPlaceholderForeground",
 			"TextControlPlaceholderForegroundPointerOver",
@@ -45,7 +45,7 @@ public static void UpdatePlaceholder(this AutoSuggestBox platformControl, ISearc
 
 		public static void UpdatePlaceholderColor(this AutoSuggestBox platformControl, ISearchBar searchBar)
 		{
-			UpdateColors(platformControl.Resources, _placeholderForegroundColorKeys,
+			UpdateColors(platformControl, platformControl.Resources, _placeholderForegroundColorKeys,
 				searchBar.PlaceholderColor?.ToPlatform());
 		}
 
@@ -54,7 +54,7 @@ public static void UpdateText(this AutoSuggestBox platformControl, ISearchBar se
 			platformControl.Text = searchBar.Text;
 		}
 
-		private static readonly string[] _foregroundColorKeys =
+		static readonly string[] _foregroundColorKeys =
 		{
 			"TextControlForeground",
 			"TextControlForegroundPointerOver",
@@ -66,7 +66,7 @@ public static void UpdateTextColor(this AutoSuggestBox platformControl, ISearchB
 		{
 			var tintBrush = searchBar.TextColor?.ToPlatform();
 
-			if (tintBrush == null)
+			if (tintBrush is null)
 			{
 				platformControl.Resources.RemoveKeys(_foregroundColorKeys);
 				platformControl.Foreground = null;
@@ -80,7 +80,7 @@ public static void UpdateTextColor(this AutoSuggestBox platformControl, ISearchB
 			platformControl.RefreshThemeResources();
 		}
 
-		private static void UpdateColors(ResourceDictionary resource, string[] keys, Brush? brush)
+		private static void UpdateColors(AutoSuggestBox platformControl, ResourceDictionary resource, string[] keys, Brush? brush)
 		{
 			if (brush is null)
 			{
@@ -90,6 +90,8 @@ private static void UpdateColors(ResourceDictionary resource, string[] keys, Bru
 			{
 				resource.SetValueForAllKey(keys, brush);
 			}
+
+			platformControl.RefreshThemeResources();
 		}
 
 		public static void UpdateFont(this AutoSuggestBox platformControl, ISearchBar searchBar, IFontManager fontManager) =>
@@ -126,14 +128,20 @@ public static void UpdateMaxLength(this AutoSuggestBox platformControl, ISearchB
 			}
 
 			if (maxLength == 0)
+			{
 				MauiAutoSuggestBox.SetIsReadOnly(platformControl, true);
+			}
 			else
+			{
 				MauiAutoSuggestBox.SetIsReadOnly(platformControl, searchBar.IsReadOnly);
+			}
 
 			var currentControlText = platformControl.Text;
 
 			if (currentControlText.Length > maxLength)
+			{
 				platformControl.Text = currentControlText.Substring(0, maxLength);
+			}
 		}
 
 		public static void UpdateIsReadOnly(this AutoSuggestBox platformControl, ISearchBar searchBar)
@@ -146,7 +154,9 @@ public static void UpdateIsTextPredictionEnabled(this AutoSuggestBox platformCon
 			var textBox = platformControl.GetFirstDescendant<TextBox>();
 
 			if (textBox is null)
+			{
 				return;
+			}
 
 			textBox.UpdateIsTextPredictionEnabled(searchBar);
 		}
@@ -156,7 +166,9 @@ public static void UpdateIsSpellCheckEnabled(this AutoSuggestBox platformControl
 			var textBox = platformControl.GetFirstDescendant<TextBox>();
 
 			if (textBox is null)
+			{
 				return;
+			}
 
 			textBox.UpdateIsSpellCheckEnabled(searchBar);
 		}
@@ -165,13 +177,15 @@ public static void UpdateKeyboard(this AutoSuggestBox platformControl, ISearchBa
 		{
 			var queryTextBox = platformControl.GetFirstDescendant<TextBox>();
 
-			if (queryTextBox == null)
+			if (queryTextBox is null)
+			{
 				return;
+			}
 
 			queryTextBox.UpdateInputScope(searchBar);
 		}
 
-		private static readonly string[] CancelButtonColorKeys =
+		static readonly string[] CancelButtonColorKeys =
 		{
 			"TextControlButtonForeground",
 			"TextControlButtonForegroundPointerOver",
@@ -183,7 +197,9 @@ internal static void UpdateCancelButtonColor(this AutoSuggestBox platformControl
 			var cancelButton = platformControl.GetDescendantByName<Button>("DeleteButton");
 
 			if (cancelButton is null)
+			{
 				return;
+			}
 
 			cancelButton.UpdateTextColor(searchBar.CancelButtonColor, CancelButtonColorKeys);
 		}