Reactive extensions handle event once

Question

If I need one handle some event I usually code like this:

            // part of browser

            UrlEventHandler docReadyDelegate = null;
            var documentReady = new UrlEventHandler((sender, args) =>
            {
                view.DocumentReady -= docReadyDelegate; // unsubscribe
                // some code here. Fired then browser's document is ready!
            });

            docReadyDelegate = documentReady;
            view.DocumentReady += docReadyDelegate; // subscribe

            view.Navigate("http://google.com");

But as I think its not optimally and not beautiful. I know it possible to use Reactive Extensions to handle event once. How?

Answer 1

Try this:

    Observable
        .FromEventPattern<UrlEventHandler, UrlEventArgs>(
            h => view.DocumentReady += h, 
            h => view.DocumentReady -= h)
        .Take(1)
        .Subscribe(se =>
        {
            /* code run only once */
        });

It will fire only once because of the .Take(1) and it will deal nicely with all of the attaching and detaching of the event handler.