I need to call a time-consuming stored procedure on an SQL Server. This
means that a single SqlCommand.ExecuteNonQuery() call might take a
couple of hours. That's why I put it into a subthread, so I can at
least show the clock running.

I would very much like to allow the user to stop this operation, but
calling Thread.Abort() only sets the ThreadState to AbortRequested.
Only when the ExecuteNonQuery() call then returns, a
ThreadAbortException is finally encountered, but this could happen a
couple of hours after clicking "Cancel", so it's not what I need.

When I debug this in VS 2005, it considers the application to be
running because of this thread until I press "Stop Debugging",
whereupon the thread is stopped immediately. So, VS 2005 is able to
terminate this process during the call. Does it do this via WinAPI
calls the way the Task Manager would (I assume), or is there a less
messy way in .NET?

Thanks
Oliver