AnonymousObserver<T> public sealed class AnonymousObserver<T> : ObserverBase<T> Class to create an IObserver<T> instance from delegate-based implementations of the On* methods. Documentation Code public AnonymousObserver(Action<T> onNext, Action<Exception> onError, Action onCompleted) Creates an observer from the specified OnNext, OnError, and OnCompleted actions. public AnonymousObserver(Action<T> onNext) Creates an observer from the specified OnNext action. public AnonymousObserver(Action<T> onNext, Action<Exception> onError) Creates an observer from the specified OnNext and OnError actions. public AnonymousObserver(Action<T> onNext, Action onCompleted) Creates an observer from the specified OnNext and OnCompleted actions.