ThreadPool.RegisterWaitForSingleObject( ) returns a RegisteredWaitHandle. To cancel a registered wait (either a new one or one that continuously executes), use Unregister( ).

public sealed class RegisteredWaitHandle : MarshalByRefObject {
// Public Instance Methods
   public bool Unregister(WaitHandle waitObject);
// Protected Instance Methods
   protected override void Finalize( );   
// overrides object
}

Hierarchy

System.Object System.MarshalByRefObject RegisteredWaitHandle

Returned By

ThreadPool.{RegisterWaitForSingleObject( ), UnsafeRegisterWaitForSingleObject( )}