What kind of problems upgrading Silverlight from v3 to v4

Question

We are contemplating building an upcoming project in Silverlight. We would be developing this in SL 4, not 3, but another developer in our organization had the experience of upgrading from v2 to v3 in the middle of a project, and losing features and functionality that MS didn't include in v3. This was some headache for him, working around this, and my team are wondering if others have had similar headaches (i.e. lack of backwards compatibility) in upgrades from v3 to v4 -- as a way to possibly predict if we're going to run into serious problems when SL goes from v4 to v5.

The application we will be building doesn't "need" advanced SL features, and could easily be built as a plain vanilla ASP.NET web application. We would like to learn to use SL, however, and this is an opportunity to do so -- but not at the expense of SL munging our future maintenance efforts by making it problematic to upgrade framework versions.

Any experiences out there?

Answer 1

2 to 3 was a bigger leap.

3 to 4 should be painless.

Read this article on Silverlight Compatibility: http://blogs.msdn.com/b/nickkramer/archive/2010/09/11/how-does-silverlight-compatibility-work.aspx

Answer 2

Your users probably wont have it and would probably need to install SL4 before they can use it

Answer 3

The automatic project conversion wizard in Visual Studio does a great job, and Silverlight 4 is mainly additions of new features (not removing of existing ones).

We have had one Silverlight project (out of a dozen) stop rendering certain controls properly with Silverlight 4, but that was down to a slight runtime engine change to Silverlight itself and likely down to us misusing the controls.

Otherwise it has been plain sailing. SL 4 is definitely the way to go. The improvements to Expression Blend 4 alone were worth the upgrade (Expression 3 tended to crash editing style templates of Telerik Rad controls).

I warn you now, once the Silverlight bug bite you, you will have trouble going back to ASP.Net :)

Hope this helps.