Allow string property binding as Color source (dotnet#9814) Fixes dot…

…net#9662 Fixes dotnet#8390

src/Controls/samples/Controls.Sample/Pages/Controls/ButtonPage.xaml

@@ -40,6 +40,12 @@
                 <Button
                     BackgroundColor="Blue"
                     Text="Button"/>
+                <Label
+                     Text="BackgroundColor (Binding)"
+                     Style="{StaticResource Headline}" />
+                 <Button 
+                     Text="Button"
+                     BackgroundColor="{Binding ButtonBackground}" />
                 <Label
                     Text="Background"
                     Style="{StaticResource Headline}" />

src/Controls/samples/Controls.Sample/Pages/Controls/ButtonPage.xaml.cs

@@ -84,6 +84,8 @@ void OnBackgroundButtonClicked(object sender, System.EventArgs e)
 
 	public class ButtonPageViewModel : BindableObject
 	{
+		public string ButtonBackground => "#fc87ad";
+
 		public ICommand ButtonCommand => new Command(OnExecuteImageButtonCommand);
 
 		void OnExecuteImageButtonCommand()

src/Controls/src/Core/BindableProperty.cs

@@ -43,6 +43,7 @@ public sealed class BindableProperty
 		{
 			{ typeof(Uri), new UriTypeConverter() },
 			{ typeof(Easing), new Maui.Converters.EasingTypeConverter() },
+			{ typeof(Maui.Graphics.Color), new ColorTypeConverter() },
 		};
 
 		static readonly Dictionary<Type, IValueConverter> KnownIValueConverters = new Dictionary<Type, IValueConverter>

src/Controls/tests/Xaml.UnitTests/ColorConverter.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="Microsoft.Maui.Controls.Xaml.UnitTests.ColorConverter">
+    <ContentPage.Content>
+        <Button        
+            x:Name="Button0"
+            Text="Button"
+            BackgroundColor="{Binding ButtonBackground}" />
+    </ContentPage.Content>
+</ContentPage>

src/Controls/tests/Xaml.UnitTests/ColorConverter.xaml.cs

@@ -0,0 +1,39 @@
+using Microsoft.Maui.Controls.Core.UnitTests;
+using Microsoft.Maui.Graphics;
+using NUnit.Framework;
+
+namespace Microsoft.Maui.Controls.Xaml.UnitTests
+{
+	public partial class ColorConverter : ContentPage
+	{
+		class Data
+		{
+			public string ButtonBackground => "#fc87ad";
+		}
+
+		public ColorConverter()
+		{
+			InitializeComponent();
+		}
+
+		public ColorConverter(bool useCompiledXaml)
+		{
+			//this stub will be replaced at compile time
+		}
+
+		[TestFixture]
+		public class Tests
+		{
+			[TestCase(false)]
+			[TestCase(true)]
+			public void StringsAreValidAsColor(bool useCompiledXaml)
+			{
+				var page = new ColorConverter(useCompiledXaml);
+				page.BindingContext = new Data();
+
+				var expected = Color.FromArgb("#fc87ad");
+				Assert.AreEqual(expected, page.Button0.BackgroundColor);
+			}
+		}
+	}
+}