TFS API TeamProjectCollection GetService<IBuildServer>() returns null object

Question

I have written below code to queue a build via api. team project collection, workitem store and version control server works fine, but i am not getting buildserver object. its always returning null. am i missing any other configuration

using (TfsTeamProjectCollection tpc = TfsTeamProjectCollectionFactory.GetTeamProjectCollection(new Uri("http://tfsserver:8080/tfs/DefaultCollection")))
{
    tpc.EnsureAuthenticated();

    // i am getting workitemstore object here
    var wiStore = tpc.GetService<WorkItemStore>();
    ....
    ....

    // i am getting version control server object here as well
    var vcs = tpc.GetService<VersionControlServer>();
    ....
    ....

    // but here i get a null object
    var bs = tpc.GetService<IBuildServer>();

    //this is what i want to do with buildserver object
    var buildDefinition = bs.GetBuildDefinition("aaa", "bbb");
    var buildRequest = buildDefinition.CreateBuildRequest();
    bs.QueueBuild(buildRequest);
}

any idea?

Answer 1

This can happen if you reference the wrong version of Microsoft.TeamFoundation.Build.Client for the TFS that you're trying to connect to. Check that you're referencing the correct version for TFS2010 (10.0.0.0 I believe).

http://pmichaels.net/2015/03/20/unable-to-get-ibuildserver-always-returning-null/