Silverlight调用WCF服务

When creating a WCF Service Application for your Silverlight application you will encounter a "cross domain" error with default configurations.  

Below I show the default Service application code (only class name changed) and made the necessary Silverlight WCF configuration change for basicHttpBinding as shown by the arrow. 

I then created a Web Service reference for both my Silverlight application and Test application.  Note that Silverlight uses Async calls while the Test project uses Sync call to obtain data.

When I run the Silverlight application I get the following error:

I added the following clientaccesspolicy.xml file per (you can copy code from it) to my WCF Service and both my Silverlight and Unit test run without issue.