Issues / Steps in downgrading silverlight 4 app to silverlight 3

What steps does it take to download a Silverlight 4 application to Silverlight 3.

I can't develop any longer with Beta 4 and made a wrong assumption that V开发者_如何学JAVAS2010 RC would be able to run Sivlerlight Beta 4 - which it unfortunately can't. VS2010 RC which was just released can only currently work with SL3. (hoping/expecting someone to hack it to work but right now it doesn't)

So I'm wondering what are the steps to download Silverlight 4 to Silverlight 3 and what do I lose and what should I watch out for.

(I realize that the answer is somewhat related to the 'opposite' of the feature list for SL4 but there's other issues - such as updating projects etc.) and perhaps some subtle things to watch out for that don't get caught by the compiler.

EDIT: IMPORTANT. There is now a workaround to get SL4 running in VS2010 RC http://translate.google.com/translate?hl=en&sl=auto&tl=en&u=http://sorokoletov.com/2010/02/hate-2-wait-silverlight-4-beta-2-vs-2010-rc/

The only problem I've seen so far is I cannot use 'dynamic' - which is fine for me. I get this error when running this code:

 dynamic userState = e.UserState;
 userState.dfo();

One or more types required to compile a dynamic expression cannot be found. Are you missing references to Microsoft.CSharp.dll and System.Core.dll?

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You could try this

A quick warning for Silverlight developers: Silverlight 3 projects are supported with the Visual Studio 2010 Release Candidate build but Silverlight 4 projects are not, and won't be until the next public Silverlight 4 release. Thus, if you are doing active Silverlight 4 development, Microsoft recommends staying with the Visual Studio 2010 Beta 2 build for now.

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Wouldn't it be easier to go back to Beta 2 instead and wait for the next public release of SL4 before moving to RC? It would save you re-coding back to SL3 which surely you'll regret as soon as VS2010 and SL4 are RTM?

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I guess this was a pipedream of mine. I only started developing with SL4 and the downgrading appears to be a very painful procedure.

They just added way too many cool features !!!

http://timheuer.com/blog/archive/2009/11/18/whats-new-in-silverlight-4-complete-guide-new-features.aspx