The Moon Upstairs

Version 2.0 can consume web services, and importantly ALL calls are asynchronous.

The XAP file is like the Flash SWF file, it is a zip file of all the DLL's.

In IIS must have XAP registered as a MIME type.

The BCL is the Base Class Library.  The isolated store will hold up to 1 MB, and you can ask the end user for more up to 10 MB.

The Silverlight List Box can be used as a Control Container.  For beginners, Corey suggested the introductory series by Scott Guthrie which can be found here. 

An overview of Expression Blend 2.5 for Silverlight developers was given by Shawn.  The current beta release has several bugs, it will crash on you.  One nice thing is that Visual Studio 2008 and Blend use the same solution file.

Shawn continued with an overview of consuming data with Silverlight. 

There is no ADO in Silverlight, but there is full support for LINQ to Objects and LINQ to XML.  Beware that LINQ projections have a bug.

The XDocument and the XMLDocument classes are available.  XMLDocument has a smaller footprint, but does not support XPath.  You can use XMLReader but it is difficult to work with.  Shaped results should be changed to simple types.

Silverlight tries to restrict you to calling a web service in the current domain only.  To complicate things, the client configuration is not read in the 2.0 Beta.

As stated in the first session, the asynchronous is used with Binding, EndPoint, and Proxy Classes.  If you are using the Visual Studio developer, a fixed port number is useful, as are observable collections.  The state service SOAP client uses a Sync call and completed Events.  When using WCF, you have a lot more configuration items to set.  The query-able end points should develop shape data themselves.

ADO.Net Data Services, AKA Astoria, exposes data over HTTP(S) using URI syntax and a REST interface.  The LINQ support hides REST, it is not available now but there is a Silverlight 2 library in the works.  The REST functions Get, Post, Put, and Delete do match the primary database CRUD functions.

For security cross domain calls  require permission.  The policy file "accesspolicy.xml" must be in the root of the server.  Usually this is an all or nothing situation, but you can use existing policies to allow and grant.

Only TCP sockets are allowed and are based on the platform (i.e. Winsock).  You can only connect to the local machine by "localhost".  The Beta 1 has only socket testing only, and on a small port range.

In the final session Shawn gave a brief overview of the DeepZoom composer and how to use a DeepZoom image in your Silverlight 2 application.