Observable（Rx）用于存储库中对象的连续（异步）流

Question

I got a Repository of type Item My goal is to have the Repository provide an Observable or basically a "stream" of Item using an Observable.

I'm a complete beginner regarding RX but think I got a good grasp of the basics. My problem has been finding a way to keep an Observable alive and manually push Item to it as they come in (which might be sockets or anything else async based). Basically a Hot Observable.

I got it working using a Subject<Item> to which I subscribe but I'm missing the power of a "regular Observable", ie LINQ queries to filter the stream. I'm afraid that I'm overlooking something or looked past a fitting approach.

Any insight or direction for a beginner like me would be highly appreciated.

Answer 1

See http://rxwiki.wikidot.com/101samples#toc47

Make your class native to IObservable

If you are about to build new system, you could consider using just IObservable.

Use Subject as backend for IObservable

 class UseSubject { public class Order { private DateTime? _paidDate; private readonly Subject<Order> _paidSubj = new Subject<Order>(); public IObservable<Order> Paid { get { return _paidSubj.AsObservable(); } } public void MarkPaid(DateTime paidDate) { _paidDate = paidDate; _paidSubj.OnNext(this); // Raise PAID event } } private static void Main() { var order = new Order(); order.Paid.Subscribe(_ => Console.WriteLine("Paid")); // Subscribe order.MarkPaid(DateTime.Now); } } 

Answer 2

You're probably missing a using System.Reactive.Linq reference, otherwise Select et. al. should show up on the Subject<T> .