Network Communication

Abstract

So far, you’ve seen XAML and how to create user interfaces in Silverlight. The next major pieces of Silverlight relate to communicating with other systems and working with data (which we’ll delve into in the next chapter). The three main communication mechanisms Silverlight provides are services via Windows Communication Foundation (WCF), direct HTTP communication via the HttpWebRequest and WebClient classes, and raw communication using sockets. Silverlight 3 introduces some significant enhancements to WCF, including improved security and a binary binding. Two other interesting aspects related to networking were also introduced in Silverlight 3. First, Silverlight is now aware of when the network is available. This gives you the ability to gracefully handle a loss of network connectivity, perhaps queuing up what the user requested for when the network comes back alive. The other new aspect is the functionality for one Silverlight application to talk directly with another Silverlight application. Before we get to the specifics of networking, though, it’s important to understand cross-domain communication restrictions in Silverlight.