In Xcode 11 Apple announced a new UI toolkit, SwiftUI.

It is built in Swift and depends on a number of features such as Associated Types and property wrappers that may be difficult to reflect in C#.

There is also some tight integration with Xcode between a preview render view and the simulator.

Research needs to be done to even answer simple questions such as "what would SwiftUI in C# mean?"

As a friendly reminder, an issue card is not a guarantee that a certain feature will be done, or done under any particular time frame. Issues allow us to document what features we do and do not have, and give the community a place to provide feedback.