It’s with some satisfaction that I’m able to fill this one under the “solved” section. I’m currently building a Reporting Services solution which generates price lists which includes images of products along with some other information. My dataset includes a column with a path for the image of a particular product, but I can’t be sure that the image actually exists in the file system which means that a call to System.IO.File.Exists is needed. Thus my trouble begins: The methods always returns false even though the file is accessible…. Hours of head scratching ensues until I find that Reporting Services includes its own policy file which doesn’t allow access to the file system.
A quick change to the file Microsoft SQL Server\MSSQL\Reporting Services\ReportServer\rssrvpolicy.config makes all the difference in the world. Initially I gave RS FullTrust just to narrow the potential sources of error to a minimum, but FileIOPermission will suffice in my case. Specifically I changed the following node from
<CodeGroup class="FirstMatchCodeGroup" version="1" PermissionSetName="Nothing">
<CodeGroup class="FirstMatchCodeGroup" version="1" PermissionSetName="FullTrust">
Also do remember that we are deailing with XML thus case very muhc matters. "Fulltrust" does not yield the same results as "FullTrust".
The opinions expressed herein are my own personal opinions and do not represent
my employer's view in any way.