Question

Is it possible to update a field of a work item using the TFS API ?

Something along this line:

WorkItemStore.GetWorkItem(Convert.ToInt32(current.WorkItemId)).State = rcbState.SelectedValue;

Answer 1

You can set update your WorkItem properties as you show above, just be sure to save them once your done with it.

Something like:

WorkItem item = WorkItemStore.GetWorkItem(Convert.ToInt32(current.WorkItemId));
item.State = rcbState.SelectedValue;
item.Save();