Problems accessing the Running Object Table

Question

In my program I use the Running Object Table (ROT) to ensure only one instance of my program is running. Since I \"inherit\" that code from a developer who unfortunately lef

Answer 1

In my experience the probability of a GUID collision, while possible appears unlikely, so it was not investigated. The first track I took was looking what could cause the AccessDeniedException. Working backward from there you can see that GetDisplayName does not explicitly throw this exception (or return anything similar).

So what does? Your code appears to be in C#. Unless I am mistaken using COM from C# will go through a primary interop. There are only two (2) interops that expose an IMoniker interface that I could find:

• System.Runtime.InteropServices.ComTypes contains IMoniker
• Microsoft.VisualStudio.OLE.Interop contains one as well IMoniker

You are talking about an application so my gut tells me you are using the runtime version. Looking at the calls I could not find a call returning any form of an Access Denied HRESULT or simething similar. The VisualStudio interop does mention the following about access and trust: Using Libraries from Partially Trusted Code. This sounded like a path to follow and would apply if your are using the Visual Studio interops.

If you are using the runtime services namespace which is contained in the mscorlib.dll assembly (which according to this page .NET Framework Assemblies Callable by Partially Trusted Code is marked as callable partially trusted code) the explanation does not appear to apply.

So now what? I did a search for AccessDeniedException and found no supported implementation other than an Microsoft.Office.Server.ApplicationRegistry.Infrastructure.AccessDeniedException class that is marked as obsolete in MSDN. The class is filed under the SharePoint 2010 class library.

So here are my questions: Which interop are you using? Is SharePoint in the mix at all? I said previously GUID collision was not suspected but now I am questioning that assumption. Are you requesting the proper object from the ROT? Is this object running under another process (meaning not yours)?