I hit a little gotcha today when using Silverlight to talk to a Service. My solution has a separate web and wcf projects. So, without thinking, it didn't suprise me that the Silverlight app running in the web site moaned about security when trying to talk to the service (http://projects.nikhilk.net/WebDevHelper is a great add-in for IE if you want to inspect the http requests on a development machine). So I placed a clientaccesspolicy.xml in the service and everything worked fine. Later it struck me that in this instance (for various reasons) the service should actually exist in the web site rather than a separate project. So I moved the service over and didn't bother to move the policy file, after all I will no longer be going cross-domain. So I was initially puzzled as to why I was getting the security faults again. The problem stems from my use of a virtual directory on my dev machine. So my web site is at something like; myBox.myCompany.com/devSite/default.aspx. However, when Silverlight looks for the domain policy it looks for at the root of the domain so; myBox.myCompany.com and unsurprisingly it cannot find the policy file there. So I just had to copy the file to the root of default site and everything was fine.

Had a strange problem today, some of the automated build tests were failing with "Bad class token". However, when I went onto the build machine and ran them via NUnit GUI they worked fine. The difference is that we'd normally run the tests via Type Mock to ensure all the mocks work correctly. When I ran NUnit GUI via TypeMock the tests would fail...well actually sometimes they'd work, sometimes they wouldn't. Yes that's a lovely position to be in <gulp>. The obvious cause to these problems was that I'd just upgraded Visual Studio 2008 to SP1. So I manually rebuilt the whole solution and everything seemed to spring back to life again. Odd problem but hopefully now someone else won't have to sit around scratching their head like I had to!

 

[Edit]

I blogged too soon. Turns out I still have the problem, but only with automated builds, if I build by hand (on the build server) then everything runs fine...weird.

[Edit]
Turns out I "just" needed to upgrade TypeMock to the latest version.

 

Whenever you play with Silverlight via Visual Studio you soon learn about the link between the Silverlight application and the web site's ClientBin folder. However, what happens if you already have a web site project and want to add a new (or existing) Silverlight project to it? Well you either manually copy the xap over after every build (no thanks) or just go the web site's properties and select the Silverlight tab and add your project to it. Easy...I hope that's not tempting fate.