cross-domain problem

Question

I am using a silverlight with wcf and when I use the .web project then it runs but when use the silver light project to run the following exception throws:

An error occurred while trying to make a request to URI 'http://localhost:9000/Services/BLWCFSvrc.svc'. This could be due to attempting to access a service in a cross-domain way without a proper cross-domain policy in place, or a policy that is unsuitable for SOAP services. You may need to contact the owner of the service to publish a cross-domain policy file and to ensure it allows SOAP-related HTTP headers to be sent. This error may also be caused by using internal types in the web service proxy without using the InternalsVisibleToAttribute attribute. Please see the inner exception for more details.

I want to use the silverlight project to debug my code

Thanks in advance

Answer 1

In order to access network resources from Silverlight, the domain hosting the resource must provide a client access policy file; this is designed this way for security reasons. See here for details: http://msdn.microsoft.com/en-us/library/cc645032%28VS.95%29.aspx

Answer 2

I think your problem is different that just having the clientaccesspolicy.xml, the fact that it runs under the web project, means that you are delivering policies, if you have those added as seperate files under the web project then they wont be deployed when you run the SL3 app seperately, but im sure you figured this out and you're delivering the policies via WCF using webHttp binding (RESTful style), if not, you should.

I think the problem is that when you run the webproject, it builds to your local IIS and executes from there, IIS will allow the SL3 app to communicate with ports/addresses different from the ones that the site is hosted on

when you run SL3 app natively, VS2008 auto generates a test html site for it to be hosted in with some default settings, and uses VS2008 built-in hosting service, which does not allow communication to an address/port different from that of the hosting address. (even though Silverlight is a client side library, VS2008 can do this)

so if you want to run the Silverlight application natively, meaning actually executing the XAP, you can deploy it to IIS, and configure IIS to deliver XAP files, or just install it and run it out of browser and let it update from IIS the deployed version

Answer 3

Just copy a clientaccesspolicy.xml file (for an example take a look at this post; you can even use this sample) into the root of your webserver (eg: c:\inetpub\wwwroot\).

This should help.