title: Cancel an asynchronous call (IAsyncResult)
body: <p>I am programming in .net WPF.</p>
  
  <p>I have a (third party) API which implements the Begin/End asynchronous call pattern. The BeginWork() function returns an IAsyncResult.</p>
  
  <p>However, there is no apparent method to cancel/abort the call, once done.</p>
  
  <p>Is there a way to have such a job stopped? If this requires the library author to provide explicitly for a cancel method, what is a way to kill this job, even ungracefully? I really need to be able to stop it somehow, as a single job may take hours to complete!</p>
  
  <p>Thanks!</p>