How to connect to TFS or Visual Studio online through API and get WorkItemStore service. Brief description of encountered issues and how to solve them.

In this post, I detail how you can access to Team Foundation Server 2013 (on premise) through its API. Once we can connect to the server, we will get an instance of a TFS service, in this example we will access to WorkItemStore, and we’ll get a list of all existing user stories in a team project. I suppouse you are familiar to TFS, and you are used to work with WorkItems) and WIQL. Ok, let’s start with a sample c# console application called TFSUserStoriesConsole. Open your Visual Studio and create a new Visual C# Console Application (File -> New -> Project -> Visual C#). Then we create a class which manage connection to TFS, and get the instance of WorkItemStore object. WorkItemStore let you to get workitems from TFS. Let me show you a piece of code:

     teamProjectCollection = new TfsTeamProjectCollection(tfsUri, myCredentials);

     teamProjectCollection.EnsureAuthenticated();

     workItemStore = teamProjectCollection.GetService<WorkItemStore>();

We connect to TFS, ensure we are connected to it, and finally we get the instance of WorkItemStore. It’s strange because workItemStore equals null and I don’t get more information about it.

The way I’ve found to get more information about this null, is create a new instance of WorkItemStore:

     WorkItemStore workItemStore = new WorkItemStore(teamProjectCollection);

In my case seems that I missed some assemblies to reference:

Type: System.IO.FileNotFoundException Message: Could not load file or assembly ‘Microsoft.TeamFoundation.WorkItemTracking.Proxy, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’ or one of its dependencies. The system cannot find the file specified. Source: Microsoft.TeamFoundation.WorkItemTracking.Client StackTrace: at Microsoft.TeamFoundation.WorkItemTracking.Client.WorkItemStore.InitializeInternal() at Microsoft.TeamFoundation.WorkItemTracking.Client.WorkItemStore.Microsoft.TeamFoundation.Client.ITfsTeamProjectCollectionObject.Initialize(TfsTeamProjectCollection teamProjectCollection) at Microsoft.TeamFoundation.Client.TfsTeamProjectCollection.InitializeTeamFoundationObject(String fullName, Object instance) at Microsoft.TeamFoundation.Client.TfsConnection.CreateServiceInstance(Assembly assembly, String fullName) at Microsoft.TeamFoundation.Client.TfsConnection.GetServiceInstance(Type serviceType, Object serviceInstance) at Microsoft.TeamFoundation.Client.TfsTeamProjectCollection.GetServiceInstance(Type serviceType, Object serviceInstance) at Microsoft.TeamFoundation.Client.TfsConnection.GetService(Type serviceType) at Microsoft.TeamFoundation.Client.TfsConnection.GetServiceT

Ok, much easier getting a stacktrace to solve the problem. I added that reference, but I get another error:

Message: Error HRESULT E_FAIL has been returned from a call to a COM component. Source: Microsoft.TeamFoundation.WorkItemTracking.Client.DataStoreLoader StackTrace: at Microsoft.TeamFoundation.WorkItemTracking.Client.DataStore.DataStoreNative.UpdateMetadata(IntPtr handle, Object rowset, String dbstamp, UInt32& changes) at Microsoft.TeamFoundation.WorkItemTracking.Client.DataStore.Datastore.UpdateMetadata(Object rowset, String dbstamp) at Microsoft.TeamFoundation.WorkItemTracking.Client.WorkItemStore.EndBackendCall(BackendCallData data) at Microsoft.TeamFoundation.WorkItemTracking.Client.WorkItemStore.RefreshCacheInternal(BackendCallData& data) at Microsoft.TeamFoundation.WorkItemTracking.Client.WorkItemStore.InitializeInternal() at Microsoft.TeamFoundation.WorkItemTracking.Client.WorkItemStore.Microsoft.TeamFoundation.Client.ITfsTeamProjectCollectionObject.Initialize(TfsTeamProjectCollection teamProjectCollection) at Microsoft.TeamFoundation.Client.TfsTeamProjectCollection.InitializeTeamFoundationObject(String fullName, Object instance) at Microsoft.TeamFoundation.Client.TfsConnection.CreateServiceInstance(Assembly assembly, String fullName) at Microsoft.TeamFoundation.Client.TfsConnection.GetServiceInstance(Type serviceType, Object serviceInstance) at Microsoft.TeamFoundation.Client.TfsTeamProjectCollection.GetServiceInstance(Type serviceType, Object serviceInstance) at Microsoft.TeamFoundation.Client.TfsConnection.GetService(Type serviceType) at Microsoft.TeamFoundation.Client.TfsConnection.GetServiceT

In this case I monitor the process with FileMon and the process ends with an access denied to folder C:\ProgramData\Microsoft Team Foundation\4.0\Cache

Once I gave write permissions to C:\ProgramData\Microsoft Team Foundation\4.0\Cache the application runs properly.

You can find this errors when you install it to a server which is not TFS data tier and without Visual Studio installed either.

Sample code can be found at Github.

Hope it helps and you save time to solve this problems.

TFS Object Model