Use WebScene with Uno Platform

Uno Platform is a first-class WebScene host for Skia desktop applications. WebScene.Backend.Uno presents the native scene through Uno's SKCanvasElement, and WebScene.Sdk.Uno provides the reusable WinUI WebSceneComponentHost for packaged Component Profile 1 applications.

The Uno host exposes the same package validation, compatibility preflight, virtual origin, lifecycle, capability bridge, interop, and diagnostics model as the Avalonia host through Uno-native WinUI XAML. It requires Uno's Skia renderer and currently supports desktop applications on osx-arm64, linux-x64, and win-x64; Uno browser, mobile, and non-Skia targets are outside this support statement.

1. Configure a Skia desktop project

Declare a supported desktop RID, enable the Skia renderer, and reference the Uno SDK host plus the matching runtime package.

<Project Sdk="Uno.Sdk/6.5.31">
  <PropertyGroup>
    <TargetFrameworks>net10.0-desktop</TargetFrameworks>
    <RuntimeIdentifier>osx-arm64</RuntimeIdentifier>
    <OutputType>Exe</OutputType>
    <UnoSingleProject>true</UnoSingleProject>
    <UnoFeatures>SkiaRenderer;</UnoFeatures>
    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="WebScene.Sdk.Uno" Version="1.0.20" />
    <PackageReference Include="WebScene.NativeEngine.Runtime.osx-arm64" Version="1.0.20" />
  </ItemGroup>
</Project>

Change osx-arm64 to linux-x64 or win-x64 in both places for the other published desktop runtimes. See Packages and deployment for the runtime files that must remain beside the application executable.

2. Mount a packaged component

Copy a component package to output without changing its manifest-relative layout:

<ItemGroup>
  <Content Include="components/MyComponent/**"
           CopyToOutputDirectory="PreserveNewest" />
</ItemGroup>

Place the host directly in Uno XAML. AutoMount defaults to true; the host validates the package, creates an isolated virtual origin, loads only declared assets, installs the capability bridge, invokes the manifest's mount export, and unmounts with the control lifetime.

<Page
    x:Class="WebSceneUnoDemo.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:webscene="using:WebScene.Sdk.Uno">
  <webscene:WebSceneComponentHost
      x:Name="ComponentHost"
      PackagePath="components/MyComponent"
      HorizontalAlignment="Stretch"
      VerticalAlignment="Stretch" />
</Page>

Use explicit lifecycle when the application must register host capabilities first:

using WebScene.Sdk;
using WebScene.Sdk.Uno;

ComponentHost.AutoMount = false;
ComponentHost.RegisterHostCapability(
    new WebSceneDelegateCapabilityHandler(
        WebSceneComponentCapabilities.Commands,
        (method, arguments, cancellationToken) =>
            HandleCommandAsync(method, arguments, cancellationToken)));

await ComponentHost.MountAsync();

MountAsync, UnmountAsync, and ReloadAsync are reusable lifecycle operations. StateChanged, ComponentMounted, ComponentUnmounted, MountFailed, DiagnosticReported, Diagnostics, and LastException expose the same host-level observability as the Avalonia component host.

The native library is resolved from WEBSCENE_NATIVE_ENGINE_LIBRARY or the application directory by default. Set NativeLibraryPath and CompilationCacheDirectory when the application needs explicit locations.

Host a document directly

Applications that own document navigation rather than a component package can use the underlying WebScene.Backend.Uno view directly:

using WebScene.Backends.Uno.Native;

var view = new UnoNativeWebSceneView();
await view.LoadAsync(
    documentUri.AbsoluteUri,
    nativeLibraryPath,
    compilationCacheDirectory);

Keep view creation, loading, reusable UnloadAsync, and final DisposeAsync on Uno's UI synchronization context. Wait until the containing control has non-zero layout before the first load.

Interoperate with JavaScript

The component host exposes its underlying view for the same ABI 3 interop boundary as Avalonia:

string result = await ComponentHost.View.EvaluateTextAsync(
    "({ title: document.title, readyState: document.readyState })");

using var interop = ComponentHost.View.CreateJavaScriptInvoker();
// Pass interop to a generated, strongly typed JavaScript facade.

The same typed interop API manifest, policy, and generated facade can be placed in a framework-neutral class library and used by both host projects. The component host installs the same webscene.host.* capability bridge and Component Profile 1 mount lifecycle used by Avalonia. See .NET and JavaScript interop.

Diagnostics and validation

RenderDiagnostics and EngineMetrics expose scene, input, frame, and cache counters. OpenV8InspectorSession provides a raw V8 Inspector session that can be forwarded by WebScene.Diagnostics.Cdp.

First-class presenter support does not broaden WebScene's bounded compatibility or security profile. Validate the exact component, package version, native RID, input, text, IME, accessibility, and shutdown behavior your product requires.