O'Reilly logo

Pro Silverlight 5 in VB by Matthew MacDonald

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Duplex Services

Ordinarily, web services use a fairly straightforward and somewhat limiting form of interaction. The client (your Silverlight application) sends a request, waits for a response, and then processes it. This is a distinctly one-way type of communication—the client must initiate every conversation.

This model is no surprise, because it's based on the underlying HTTP protocol. Browsers request web resources, but websites can never initiate connections and transmit information to clients without first being asked. Although this model makes sense, it prevents you from building certain types of applications (such as chat servers) and implementing certain types of features (such as notification). Fortunately, there are several ways to ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required