Good introduction to the .NET Reactive Framework

Question

Aside from the Microsoft documentation, does anyone know of a good introduction and tutorial to the Microsoft Reactive (Rx) framework?

Also, could someone articulate a good example (with code) of a programming problem that is challenging to solve using conventional asynchronous coding techniques that Reactive makes easier.

Answer 1

You may find these series of articles (there are 4) about reactive linq may be useful: http://tomasp.net/blog/reactive-ii-csevents.aspx

He has an example of writing a game using it, so it should hopefully be what you are looking for.

Answer 2

Does your "excluding Microsoft documentation" clause extend to the videos on Channel 9?

From the creator of the reactive framework Erik Meijer: - Expert to Expert: Brian Beckman and Erik Meijer - Inside the .NET Reactive Framework (Rx)

Brand new: Getting Started with Rx Extensions for .NET

Answer 3

Hello,

I also found following link on CodeBetter.com Introducing the Reactive Framework Part I

There is a sequel to the first part on the same site.

Hope this will help you.

Answer 4

Here's an example of something that is easy to do with reactive programming, but messy (if not challenging) with classic events, it draws lines while the mouse button is down. It is readable, there is no explicit state handling:

var pen = new Pen(Color.Red, 3);
var graphics = this.CreateGraphics();

var mouseMoveWhileDown = 
    from md in this.GetMouseDown()
    from mv in this.GetMouseMove().Until(this.GetMouseUp())
    select new Point(mv.X, mv.Y);

mouseMoveWhileDown
    .Pairwise()
    .Subscribe(tup => graphics.DrawLine(pen, tup.Item1, tup.Item2));

(I must confess that in that example, Pairwise() is home-grown...)

The most important thing about IObservable is that it is 'composable', just like IEnumerable.

I thouroughly recommend the video mentioned in another answer. In fact there are several different videos on the subject on Channel9:

Answer 5

MSDN Site for Rx-Framework

Some interesting Videos on cannel9

Kim Hamilton and Wes Dyer: Inside .NET Rx and IObservable/IObserver in the BCL (VS 2010)

An interview with the creator from Rx Expert to Expert: Brian Beckman and Erik Meijer - Inside the .NET Reactive Framework (Rx)

An introduction from the creator for Rx

• E2E: Erik Meijer and Wes Dyer - Reactive Framework (Rx) Under the Hood 1 of 2
• E2E: Erik Meijer and Wes Dyer - Reactive Framework (Rx) Under the Hood 2 of 2

Answer 6

Go through these articles, and in particular, download the related source code and play with it.

• Part I - System.Reactive or the .NET Reactive Extensions (Rx) – Concepts and First Look
• Part II - LINQ To Events - More on .NET Reactive Extensions (Rx)
• Part III - LINQ To Events - Generating GetEventName() Wrapper Methods using T4 Text Templates

Trust this will help

Answer 7

Here's a wiki site with lots of code examples demonstrating how to us different features of the .NET Rx framework: http://rxwiki.wikidot.com/101samples

I found this to be the most comprehensive site out there, and the one that's quickest to get started with.

Answer 8

Once you have gone through some of the basic stuff including the HandsOnLab make sure you check out Lee Campbell's Hot and Cold Observables which took some of the arcane mystery out of Rx for me :)