<PackageReference Include="System.Reactive" Version="4.1.3" />

ControlObservable

public static class ControlObservable
Provides a set of static methods for subscribing to IObservables using Windows Forms controls.
public static IObservable<TSource> ObserveOn<TSource>(this IObservable<TSource> source, Control control)

Wraps the source sequence in order to run its observer callbacks on the Windows Forms message loop associated with the specified control.

public static IObservable<TSource> SubscribeOn<TSource>(this IObservable<TSource> source, Control control)

Wraps the source sequence in order to run its subscription and unsubscription logic on the Windows Forms message loop associated with the specified control.