[X] Support DynResources as AppThemeBinding values

src/Controls/src/Core/AppThemeBinding.cs

@@ -1,6 +1,7 @@
 #nullable disable
 using System;
 using Microsoft.Maui.ApplicationModel;
+using Microsoft.Maui.Controls.Internals;
 
 namespace Microsoft.Maui.Controls
 {
@@ -61,7 +62,13 @@ void ApplyCore(bool dispatch = false)
 			else
 				Set();
 
-			void Set() => target.SetValueCore(_targetProperty, GetValue(), Internals.SetValueFlags.ClearDynamicResource, BindableObject.SetValuePrivateFlags.Default | BindableObject.SetValuePrivateFlags.Converted, specificity);
+			void Set() {
+				var value = GetValue();
+				if (value is DynamicResource dynamicResource)
+					target.SetDynamicResource(_targetProperty, dynamicResource.Key, specificity);
+				else
+					target.SetValueCore(_targetProperty, value, Internals.SetValueFlags.ClearDynamicResource, BindableObject.SetValuePrivateFlags.Default | BindableObject.SetValuePrivateFlags.Converted, specificity);
+			};
 		}
 
 		object _light;

src/Controls/tests/Xaml.UnitTests/Issues/Maui13619.xaml

@@ -0,0 +1,20 @@
+<?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"
+             xmlns:d="http://schemas.microsoft.com/dotnet/2021/maui/design"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             xmlns:local="clr-namespace:Microsoft.Maui.Controls.Xaml.UnitTests"
+             x:Class="Microsoft.Maui.Controls.Xaml.UnitTests.Maui13619">
+    <ContentPage.Resources>
+        <Color x:Key="Primary">DarkGray</Color>
+        <Color x:Key="Secondary">HotPink</Color>
+        <Color x:Key="Tertiary">Yellow</Color>
+        <Style TargetType="Label" x:Key="labelStyle" >
+            <Setter Property="Padding" Value="0"/>
+            <Setter Property="TextColor" Value="{AppThemeBinding Light={StaticResource Secondary}, Dark={StaticResource Primary}}" />
+            <Setter Property="BackgroundColor" Value="{AppThemeBinding Light={DynamicResource Primary}, Dark={DynamicResource Secondary}}" />
+        </Style>
+    </ContentPage.Resources>
+    <Label x:Name="label0"
+           Style="{StaticResource labelStyle}"/>
+</ContentPage>

src/Controls/tests/Xaml.UnitTests/Issues/Maui13619.xaml.cs

@@ -0,0 +1,39 @@
+using System;
+using Microsoft.Maui.ApplicationModel;
+using Microsoft.Maui.Controls.Core.UnitTests;
+using Microsoft.Maui.Graphics;
+using Microsoft.Maui.Devices;
+using NUnit.Framework;
+
+namespace Microsoft.Maui.Controls.Xaml.UnitTests
+{
+
+
+	public partial class Maui13619 : ContentPage
+	{
+		public Maui13619() => InitializeComponent();
+		public Maui13619(bool useCompiledXaml)
+		{
+			//this stub will be replaced at compile time
+		}
+
+		[TestFixture]
+		class Tests
+		{
+			[SetUp] public void Setup() => AppInfo.SetCurrent(new MockAppInfo());
+			[TearDown] public void TearDown() => AppInfo.SetCurrent(null);
+
+			[Test]
+			public void AppThemeBindingAndDynamicResource([Values(false, true)] bool useCompiledXaml)
+			{
+				var page = new Maui13619(useCompiledXaml);
+				Assert.That(page.label0.TextColor, Is.EqualTo(Colors.HotPink));
+				Assert.That(page.label0.BackgroundColor, Is.EqualTo(Colors.DarkGray));
+
+				page.Resources["Primary"] = Colors.SlateGray;
+				Assert.That(page.label0.BackgroundColor, Is.EqualTo(Colors.SlateGray));
+
+			}
+		}
+	}
+}