private void TestCountOfType() { int hr; int c, c1; IAMTimelineObj pTrack1Obj; hr = m_pTimeline.AddGroup((IAMTimelineObj)m_pVideoGroup); DESError.ThrowExceptionForHR(hr); hr = m_pTimeline.CreateEmptyNode(out pTrack1Obj, TimelineMajorType.Track); DESError.ThrowExceptionForHR(hr); // tell the composition about the track IAMTimelineComp pRootComp = (IAMTimelineComp)m_pVideoGroup; hr = pRootComp.VTrackInsBefore(pTrack1Obj, -1); DESError.ThrowExceptionForHR(hr); hr = m_pTimeline.GetCountOfType(0, out c, out c1, TimelineMajorType.Track); DESError.ThrowExceptionForHR(hr); Debug.Assert(c == 1 && c1 == 2, "GetCountOfType"); }