实施Web服务回调

Question

I have a winforms C# desktop application. I have a polling web service to my server to retrieve messages as and when they come in. Is there a way of implementing a callback web service from my desktop to the server instead of polling the web service? Is this what asynchronous web services are about?

Thanks

Answer 1

There are several approaches to achieve this: one the one Hand, you can start a request to the server with a very long timeout. Let the server wait for a new message (and assert that the request does not timeout on the Server side) and return the request once there is one. If the request times out, issue a new one.
In WCF, there are some other techniques like Duplex Services to solve this.