[X] allow x:Type extension for BPConverter

- fixes #18324

src/Controls/src/Build.Tasks/CompiledConverters/BindablePropertyConverter.cs

@@ -56,7 +56,14 @@ public FieldReference GetBindablePropertyFieldReference(string value, ILContext
 					}
 				}
 				else if ((node.Parent as ElementNode)?.XmlType.NamespaceUri == XamlParser.MauiUri && (node.Parent as ElementNode)?.XmlType.Name == nameof(Trigger))
-					typeName = ((node.Parent as ElementNode).Properties[new XmlName("", "TargetType")] as ValueNode).Value as string;
+				{
+					var targetTypeNode = (node.Parent as ElementNode).Properties[new XmlName("", "TargetType")];
+					if (targetTypeNode is ValueNode valueNode)
+						typeName = valueNode.Value as string;
+					else if (targetTypeNode is ElementNode elementNode && elementNode.XmlType.Name == "TypeExtension")
+						typeName = (elementNode.Properties[new XmlName("", "TypeName")] as ValueNode).Value as string;
+
+				}
 				propertyName = parts[0];
 			}
 			else if (parts.Length == 2)

src/Controls/tests/Xaml.UnitTests/Issues/Maui18324.xaml

@@ -0,0 +1,23 @@
+<?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:local="clr-namespace:Microsoft.Maui.Controls.Xaml.UnitTests"
+             x:Class="Microsoft.Maui.Controls.Xaml.UnitTests.Maui18324">
+    <ImageButton x:Name="imageButton">
+        <ImageButton.Style>
+            <Style TargetType="ImageButton">
+               <Style.Triggers>
+            <Trigger TargetType="{x:Type ImageButton}"
+                     Property="IsEnabled"
+                     Value="True">
+                <Setter Property="BackgroundColor"
+                        Value="Yellow" />
+            </Trigger>
+        </Style.Triggers>
+
+            </Style>
+
+        </ImageButton.Style>
+
+    </ImageButton>
+</ContentPage>

src/Controls/tests/Xaml.UnitTests/Issues/Maui18324.xaml.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Globalization;
+using System.Linq;
+using Microsoft.Maui.ApplicationModel;
+using Microsoft.Maui.Controls.Core.UnitTests;
+using Microsoft.Maui.Controls.Shapes;
+using Microsoft.Maui.Devices;
+using Microsoft.Maui.Dispatching;
+
+using Microsoft.Maui.Graphics;
+using Microsoft.Maui.UnitTests;
+using NUnit.Framework;
+
+namespace Microsoft.Maui.Controls.Xaml.UnitTests;
+
+public partial class Maui18324 : ContentPage
+{
+
+	public Maui18324() => InitializeComponent();
+
+	public Maui18324(bool useCompiledXaml)
+	{
+		//this stub will be replaced at compile time
+	}
+
+	[TestFixture]
+	class Test
+	{
+		[SetUp]
+		public void Setup()
+		{
+			Application.SetCurrentApplication(new MockApplication());
+			DispatcherProvider.SetCurrent(new DispatcherProviderStub());
+		}
+
+
+		[TearDown] public void TearDown() => AppInfo.SetCurrent(null);
+
+		[Test]
+		public void xTypeShoudntCrash([Values(false, true)] bool useCompiledXaml)
+		{
+			if (useCompiledXaml)
+				MockCompiler.Compile(typeof(Maui18324));
+			var page = new Maui18324(useCompiledXaml);
+		}
+	}
+}