Make complied bindings use TypeConverters again.

.ncrunch/Avalonia.FreeDesktop.net6.0.v3.ncrunchproject

@@ -0,0 +1,5 @@
+<ProjectConfiguration>
+  <Settings>
+    <IgnoreThisComponentCompletely>True</IgnoreThisComponentCompletely>
+  </Settings>
+</ProjectConfiguration>

.ncrunch/Avalonia.FreeDesktop.netstandard2.0.v3.ncrunchproject

@@ -0,0 +1,5 @@
+<ProjectConfiguration>
+  <Settings>
+    <IgnoreThisComponentCompletely>True</IgnoreThisComponentCompletely>
+  </Settings>
+</ProjectConfiguration>

.ncrunch/Avalonia.Themes.Simple.net6.0.v3.ncrunchproject

@@ -1,5 +1,8 @@
 <ProjectConfiguration>
   <Settings>
+    <AdditionalFilesToIncludeForProject>
+      <Value>..\Avalonia.Themes.Fluent\Strings\InvariantResources.xaml</Value>
+    </AdditionalFilesToIncludeForProject>
     <InstrumentOutputAssembly>False</InstrumentOutputAssembly>
   </Settings>
 </ProjectConfiguration>

.ncrunch/Avalonia.Themes.Simple.netstandard2.0.v3.ncrunchproject

@@ -1,5 +1,8 @@
 <ProjectConfiguration>
   <Settings>
+    <AdditionalFilesToIncludeForProject>
+      <Value>..\Avalonia.Themes.Fluent\Strings\InvariantResources.xaml</Value>
+    </AdditionalFilesToIncludeForProject>
     <InstrumentOutputAssembly>False</InstrumentOutputAssembly>
   </Settings>
 </ProjectConfiguration>

.ncrunch/Avalonia.X11.net6.0.v3.ncrunchproject

@@ -0,0 +1,5 @@
+<ProjectConfiguration>
+  <Settings>
+    <IgnoreThisComponentCompletely>True</IgnoreThisComponentCompletely>
+  </Settings>
+</ProjectConfiguration>

.ncrunch/Avalonia.X11.netstandard2.0.v3.ncrunchproject

@@ -0,0 +1,5 @@
+<ProjectConfiguration>
+  <Settings>
+    <IgnoreThisComponentCompletely>True</IgnoreThisComponentCompletely>
+  </Settings>
+</ProjectConfiguration>

src/Avalonia.Base/Data/Core/TargetTypeConverter.cs

@@ -5,6 +5,7 @@
 using System.Windows.Input;
 using Avalonia.Utilities;
 using static Avalonia.Utilities.TypeUtilities;
+using System.ComponentModel;
 
 namespace Avalonia.Data.Core;
 
@@ -65,6 +66,40 @@ public override bool TryConvert(object? value, Type type, CultureInfo culture, o
                 return true;
             }
 
+#pragma warning disable IL2026
+#pragma warning disable IL2067
+            // TODO: TypeConverters are not trimming friendly in some edge cases, we probably need
+            // to make compiled bindings emit conversion code at compile-time.
+            var toTypeConverter = TypeDescriptor.GetConverter(t);
+            var from = value.GetType();
+
+            if (toTypeConverter.CanConvertFrom(from))
+            {
+                result = toTypeConverter.ConvertFrom(null, culture, value);
+                return true;
+            }
+
+            var fromTypeConverter = TypeDescriptor.GetConverter(from);
+
+            if (fromTypeConverter.CanConvertTo(t))
+            {
+                result = fromTypeConverter.ConvertTo(null, culture, value, t);
+                return true;
+            }
+
+            // TODO: This requires reflection: we probably need to make compiled bindings emit
+            // conversion code at compile-time.
+            if (FindTypeConversionOperatorMethod(
+                value.GetType(),
+                t,
+                OperatorType.Implicit | OperatorType.Explicit) is { } cast)
+            {
+                result = cast.Invoke(null, new[] { value });
+                return true;
+            }
+#pragma warning restore IL2067
+#pragma warning restore IL2026
+
             if (value is IConvertible convertible)
             {
                 try
@@ -79,17 +114,6 @@ public override bool TryConvert(object? value, Type type, CultureInfo culture, o
                 }
             }
 
-            // TODO: This requires reflection: we probably need to make compiled bindings emit
-            // conversion code at compile-time.
-            if (FindTypeConversionOperatorMethod(
-                value.GetType(), 
-                t, 
-                OperatorType.Implicit | OperatorType.Explicit) is { } cast)
-            {
-                result = cast.Invoke(null, new[] { value });
-                return true;
-            }
-
             result = null;
             return false;
         }

tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests.cs

@@ -6,6 +6,8 @@
 using Avalonia.Controls.Presenters;
 using Avalonia.Data;
 using Avalonia.Data.Converters;
+using Avalonia.Media;
+using Avalonia.Media.Immutable;
 using Avalonia.UnitTests;
 using Avalonia.VisualTree;
 using Xunit;
@@ -94,6 +96,28 @@ public void MultiBinding_TemplatedParent_Works()
                 Assert.Equal("Foo,Bar", target.Text);
             }
         }
+
+        [Fact]
+        public void Can_Bind_Brush_to_Hex_String()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
+        xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.Data;assembly=Avalonia.Markup.Xaml.UnitTests'>
+    <Border Background='{Binding HexString}'/>
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var border = (Border)window.Content;
+                window.DataContext = new { HexString = "#ff0000" };
+
+                window.ApplyTemplate();
+
+                var brush = Assert.IsType<ImmutableSolidColorBrush>(border.Background);
+                Assert.Equal(Colors.Red, brush.Color);
+            }
+        }
     }
 
     public class ConcatConverter : IMultiValueConverter

tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs

@@ -24,6 +24,7 @@
 using Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings;
 using Avalonia.Markup.Xaml.Templates;
 using Avalonia.Media;
+using Avalonia.Media.Immutable;
 using Avalonia.Metadata;
 using Avalonia.UnitTests;
 using Xunit;
@@ -2022,6 +2023,30 @@ public void Can_Use_Implicit_Conversions()
             }
         }
 
+        [Fact]
+        public void Can_Bind_Brush_To_Hex_String()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = $@"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
+        xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'
+        x:DataType='local:TestData'
+        x:CompileBindings='True'>
+    <TextBlock Name='textBlock' Background='{{Binding StringProperty}}'/>
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var textBlock = window.FindControl<TextBlock>("textBlock");
+
+                var dataContext = new TestData { StringProperty = "#ff0000" };
+                window.DataContext = dataContext;
+
+                var brush = Assert.IsType<ImmutableSolidColorBrush>(textBlock!.Background);
+                Assert.Equal(Colors.Red, brush.Color);
+            }
+        }
+
         static void Throws(string type, Action cb)
         {
             try