Reactive Extensions for .NET Developers

Question

I found some information about this but I have several confusion regarding this. So when we need to use this RX.NET.

What are the important of using this items? When I need to use this?

Answer 1

As with every toolset, it can shape how you approach problems. Given a hammer, all your problems may become nails. It is the same with Rx.NET. It gives you a new approach. Whether you choose to use this approach for a particular problem is up to you, and as with any tool or technology, there are plusses and minuses. You will need to study and gain experience to make those sort of complex judgements for yourself.

For starters, Rx.NET allows you to cultivate the approach of programming 'reactively.' This is akin to functional programming, in the sense that you declare behavour as being composed of underlying behavior. Rx.NET allows you to specify functions over streams to give new streams. This powerful technique can be applied to almost any problem you can imagine.

For example, a program using Linq and Rx.NET to draw mouse movements as points on a screen within a bounding box would like something like:

mouseMovements.Where(box.Contains(m)).Subscribe(DrawPoint)

where mouseMovements would be your mouse event as an observable

You could declare the

myPointsInBox = mouseMovements.Where(box.Contains(m))

as its own observable and have multiple subscribers:

myPointsInBox.Subscribe(DrawPoint)
myPointsInBox.Subscribe(ConnectWithLines)
myPointsInBox.Subscribe(UpdatePointCounter)

you can make streams from streams

var everyThousandthPoint= myPointsInBox.Buffer(….).Select(…)

and then do things with them

   everyThousandthPoint.Subscribe(FlashPointCounter)

You get the idea.