Why only basicHttpBinding with silverlight and wcf?

Question

Exact duplicate: http://stackoverflow.com/questions/661479/why-does-silverlight-2-only-support-wcf-basichttp-binding

Why only basicHttpBinding with silverlight and wcf? Perhaps you have a link that covers this, you don't have to do a bunch of typing :+>

Answer 1

Hm, I am pretty sure this is duplicate, but can't find it. I think the short answer is that BasicHttpBinding is the only binding that works in Partial Trust.

(EDIT: found the dup, linked in question now)

Answer 2

I found several links for this but no definitive answer. Smells like Silverlight was designed against ASMX web services for Web service style communication and the way to get WCF to play with older clients expecting an ASMX web service is to use the basicHttp binding.

This link gives you a fully worked example (using Beta2 of Silverlight).
http://msdn.microsoft.com/en-us/magazine/cc794260.aspx

A standard WCF service can be invoked by a Silverlight app as long as the Silverlight app has a binding of type basicHttpBinding. You must either make sure you change the default binding of the WCF service from wsHttpBinding to basic­HttpBinding or create a new binding of type basicHttpBinding

This Reference says the same thing but again offers no explanation. http://timheuer.com/blog/archive/2008/03/14/calling-web-services-with-silverlight-2.aspx

Silverlight communicates using the BasicHttpBinding for WCF

Answer 3

A couple of answers: (1) Silverlight 4 now makes the Net.TCP binding available, which is darned handy when it's not blocked, since it's dramatically faster (see here for details). So clearly there's nothing inherent in the Silverlight architecture which prevents it from using other bindings.

(2) As for why Silverlight doesn't make use of the other WS* Http-based bindings, it's just a guess, but I wouldn't be surprised if those bindings made use of the HTTP protocol in ways that Silverlight's limited HTTP stack won't support, probably for security reasons. For instance, I know that Silverlight limits the content headers that you can place on an HTTP request, and if any of the WS-* protocols require custom headers, or headers that might represent a security risk, MS would want to prevent that.

(3) Of course, it's also possible that MS just hasn't gotten around to it yet. They've done a lot with Silverlight in the last couple years -- but presumably they have to prioritize their features.