Fix x:Bind interface property access on concrete types without public members

[Copilot]

GitHub Issue: closes #

PR Type:

• 🐞 Bugfix

What is the current behavior? 🤔

x:Bind fails when accessing interface properties on concrete types that don't expose those properties publicly. For example:

<!-- ViewModel has: IReadOnlyList<T> Items { get; } = new[] { ... } -->
<TextBlock Text="{x:Bind Model.Items.Count, Mode=OneWay}" />

Fails with:

The [Count] property getter does not exist on type [T[]]

Arrays implement IReadOnlyList<T>.Count but only expose Length directly. x:Bind uses reflection on the concrete type rather than checking interface implementations.

What is the new behavior? 🚀

BindingPropertyHelper now checks implemented interfaces when a property is not found in the type hierarchy:

Core changes:

• GetPropertyInfo: After checking class hierarchy, iterates through GetInterfaces() to find matching properties
• GetIndexerInfo: Same pattern for interface indexers (e.g., IReadOnlyList<T>[index])
• Priority: Concrete type properties found before interface properties (preserves existing behavior)

Trimming support:

• Added DynamicallyAccessedMemberTypes.Interfaces annotation
• Added UnconditionalSuppressMessage for GetInterfaces() calls

Tests added:

• Runtime test page validating array/List Count access via x:Bind
• Unit tests for BindingPropertyHelper covering arrays, lists, indexers, and priority ordering

PR Checklist ✅

Please check if your PR fulfills the following requirements:

• 📝 Commits must be following the Conventional Commits specification.
• 🧪 Added Runtime tests, UI tests, or a manual test sample for the changes have been added (for bug fixes / features) (if applicable)
• 📚 Docs have been added/updated which fit documentation template (for bug fixes / features)
• 🖼️ Validated PR Screenshots Compare Test Run results.
• ❗ Contains NO breaking changes

Other information ℹ️

Matches WinUI3/WinAppSDK behavior where x:Bind correctly resolves interface properties regardless of concrete type implementation.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>x:Bind appears to be doing reflection on concrete type instead of a compiled binding to actual property type.</issue_title>
<issue_description>### Current behavior 🐛

View model:

[ObservableProperty]
public partial IReadOnlyList<RepositorySummary> Repositories { get; private set; } = [];

View:

<TextBlock Text="No repositories found." Visibility="{x:Bind suxc:Visible.IfZero(Model.Repositories.Count), Mode=OneWay}"  />

<TextBlock Text="Repositories found." Visibility="{x:Bind suxc:Visible.IfNotZero(Model.Repositories.Count), Mode=OneWay}"  />

If the concrete type returned by Model.Repositories does not have a public Count property (i.e. if it is an array [with a Length property instead] or a collection expression result [with only explicitly implemented interface members]), you get the following error and the bindings above fail:

fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
      The [Count] property getter does not exist on type [DropDoc.DataContracts.Repositories.RepositorySummary[]]

Expected behavior 🎯

x:Bind is a compiled binding - it should be accessing IReadOnlyList<RepositorySummary>.Count directly to get the value, not attempting to get it via reflection from a Count property on the concrete type returned by the property. This works fine in WinAppSdk/WinUI3, just not on Uno targets.

How to reproduce it (as minimally and precisely as possible) 🔬

See above.

Workaround 🛠️

Need to return a concrete type with a public Count property.

Renderer 🎨

• Skia
• Native

Affected platforms 📱💻🖥️

All platforms 🌍 (except WinAppSdk)

Uno.Sdk version (and other relevant versions) 📦

6.5.0-dev.100

IDE version 🧑‍💻

No response

Anything else we need to know? 💬

No response</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes x:Bind appears to be doing reflection on concrete type instead of a compiled binding to actual property type. #22223

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[jeromelaban]

This is not needed

[unodevops]

🤖 Your WebAssembly Skia Sample App stage site is ready! Visit it here: https://unowasmprstaging.z20.web.core.windows.net/pr-22325/wasm-skia-net9/index.html

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[Xiaoy312]

originalType.GetInterfaces() also return Type[]s
we could wrap the whole thing in a single foreach loop instead of duplicating the code:

IEnumerable<Type> EnumerateAllTypesAndInterfaces(Type type)
{
	for (var t = type; t is { }; t = t.BaseType)
	{
		yield return t;
	}
	foreach (var t in type.GetInterfaces())
	{
		yield return t;
	}
}

XyzInfo? GetXyzInfo(Type type, string name, bool allowPrivateMembers)
{
	var flags = 
		BindingFlags.Public |
		(allowPrivateMembers ? BindingFlags.NonPublic : BindingFlags.Default) |
		BindingFlags.Instance | BindingFlags.Static;
	foreach (var t in EnumerateAllTypesAndInterfaces())
	{
		var info = t.GetXyz(...,
			flags | (!info.IsInterface ? BindingFlags.DeclaredOnly : BindingFlags.Default), ...
		)
		...
	}
}

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