title: Exit a workflow?
body: <p>Is there a way to exit a workflow more gracefully than throwing an <code>InvalidWorkflowException</code>? I'm writing an activity (that interacts with an SQL database) that needs to short-circuit if an operation fails. </p>
  
  <p>I know it could be split it up into multiple steps/activities and chain them, but could I set the state of my execution from within an activity?</p>
  
  <p>Something like <code>this.currentContext.SetState(Cancelled)</code>?</p>