TFS API TestManagementService always returns null

Question

I'm trying to get test plans by using TFS API.

TfsTeamProjectCollection tfs = TfsTeamProjectCollectionFactory.GetTeamProjectCollection(new Uri("http://xxxxxxx:8080/tfs/DefaultCollection"));

var service = (ITestManagementService)tfs.GetService(typeof(ITestManagementService));

The variable "service" always returns null.

Do you have any idea, why?

Answer 1

Try to make sure you that you are authenticated to the Team Project Collection before calling the Get Service command. This code snippet works correctly for me:

TfsTeamProjectCollection tpc = TfsTeamProjectCollectionFactory.GetTeamProjectCollection(new Uri("https://tfs.companyname.com/tfs/DefaultCollection"));
tpc.EnsureAuthenticated();

ITestManagementService service = tpc.GetService<ITestManagementService>();

Answer 2

Perhaps you're linking against different versions of reference assemblies, mixing different versions of Visual Studio assemblies? Example:

• Microsoft.TeamFoundation.Client v11.0 (VS 2012)
• Microsoft.TeamFoundation.TestManagement.Client v12.0 (VS 2013)

I had the same problem of GetService<ITestManagementService>() always returning null, even when GetService<VersionControlServer>() would return good (non-null) value.

The solution posted in MSDN - VersionControlServer always returns null worked for me: I had references to some v11.0 (VS2012) and v12.0 (VS2013) assemblies. Changing all references to v11.0 fixed it for me.