Code sample: POCOs (Silverlight)

This sample application shows how to query for POCO objects in your DevForce application.  It will define the POCO class, add a service provider, and extend the EntityManager to make client-side querying easier.

• Platform: Silverlight
• Language: C#, VB
• Download: POCOs (Silverlight)
  
  

Problem

You need to retrieve data from a non-relational data source, such as XML.

Solution

Using DevForce POCO support you can work with POCO objects in the same way you work with DevForce database-backed entities.  This sample shows how to provide query capabilities to your application.  

In the sample we'll define a POCO class named "State" whose data source is an XML file containing information on US states.  The Silverlight application will issue an asynchronous LINQ query for these objects, just as it would for other DevForce entities. This is possible because we've added an extension method to the EntityManager which allows for easier querying.  On the server, we've implemented a service provider to fulfill the actual query request.  

On the client, our application loads the data for the lower 49 states by making this simple query: