In the previous article, Dinesh Sodani explained what
Silverlight is and how it is being used more and more to develop business applications. In the next one, he discusses the
Silverlight application life cycle.
Source: Beyond Relational
As you may figure out, There is No Life Cycle. If you have a button control on the Silverlight app and press it, there will never we a post back, back to the server. The click event will just simply be fired of on the client-side; it's where the code is executed. To get data from a server, you can for use a WCF service, Web Service, Web Client, .NET RIA Services etc... They will make the call to the server from the client side for you.