Proposal: Expose XamlDirect for WinUI

[mikernet]

Proposal: XamlDirect for WinUI

Summary

Not sure if I am missing something but XamlDirect APIs that were available for UWP do not appear to be present in WinUI 3.

I was interested in using them to improve the performance of Uno Platform's C# Markup feature when running on WinAppSDK by using XamlDirect where possible.

Rationale

The documentation for XamlDirect explains the rationale better than I ever could: https://learn.microsoft.com/en-us/uwp/api/windows.ui.xaml.core.direct?view=winrt-22621#remarks

XamlDirect is purpose built for middleware that predominantly use imperative APIs to create UI instead of markup. With XamlDirect APIs, you can achieve performance parity with the XAML parser even when creating UI imperatively in code.

XamlDirect APIs can be used side-by-side with traditional APIs and take advantage of the pay for play performance improvements.

It was designed specifically for this exact scenario.

Scope

Expose all of UWP's XamlDirect-related functionality.

[karkarl]

XamlDirect was a retired experiment that was not carried to WinUI3. Closing as not planned.