private SqlCommand _cmd;
// threads signal these when done
private AutoResetEvent _e1 = new AutoResetEvent ( false );
private AutoResetEvent _e2 = new AutoResetEvent ( false );

void IssueQuery ( ) {
   SqlDataReader r;
   int rows = 0;
   try {
      r = _cmd.ExecuteReader ( );
      do {
         while ( r.Read ( ) ) {
            rows++;
         }
      } while ( r.NextResult ( ) );
      Response.Write ( "FAILED: execution should not have finished, {0} rows read!", rows );
   }
   catch ( ) {
      Response.Write ( "PASSED:  Got expected exception!" );
   }
_e1.Set ( );
}

void CancelQuery ( ) {
   System.Threading.Thread.Sleep ( 500 );
   _cmd.Cancel ( );
   _e2.Set ( );
}

void CancelTest ( ) {
   SqlConnection conn = new SqlConnection (
      "Data Source=localhost; Integrated Security=SSPI;Initial Catalog=northwind;" );
   conn.Open ( );
   _cmd = new SqlCommand ( null, conn );

   AutoResetEvent [ ] evs = new AutoResetEvent [ 2 ];
   evs [ 0 ] = _e1;
   evs [ 1 ] = _e2;

   Thread t1 = new Thread ( new ThreadStart ( this.IssueQuery ) );
   Thread t2 = new Thread ( new ThreadStart ( this.CancelQuery ) );
   t1 = new Thread ( new ThreadStart ( this.IssueQuery ) );
   t2 = new Thread ( new ThreadStart ( this.CancelQuery ) );

   // cancel operation while results are coming back
   _cmd.CommandText = "SELECT * FROM orders, products";
   t1.Start ( );
   t2.Start ( );
   WaitHandle.WaitAll ( evs );
   conn.Close ( );
}

Private _cmd As SqlCommand
' threads signal these when done
Private _e1 As AutoResetEvent = New AutoResetEvent ( False )
Private _e2 As AutoResetEvent = New AutoResetEvent ( False )

Public Sub IssueQuery ( )
   Dim r As SqlDataReader
   Dim rows As Integer = 0
   Try
      r = _cmd.ExecuteReader ( )
      Do
         Do While r.Read
            rows = rows + 1
         Loop
      Loop While r.NextResult ( )
      Response.Write ( "FAILED: execution should not have finished, {0} rows read!", rows )

   Catch
       Response.Write ( "PASSED:  Got expected exception!" )
   End Try
   _e1.Set ( )
End Sub

Public Sub CancelQuery ( )
   System.Threading.Thread.Sleep ( 500 )
   _cmd.Cancel ( )
   _e2.Set ( )
End Sub

Public Sub CancelTest ( )
   Dim conn As SqlConnection = New SqlConnection ( _
      "Data Source=localhost; Integrated Security=SSPI;Initial Catalog=northwind;" )
   conn.Open ( )
   Dim _cmd As SqlCommand = New SqlCommand ( "", conn )

   Dim evs ( 2 ) As AutoResetEvent
      evs ( 0 ) = _e1
      evs ( 1 ) = _e2

   Dim t1Start As ThreadStart = New ThreadStart ( AddressOf IssueQuery )
   Dim t2Start As ThreadStart = New ThreadStart ( AddressOf CancelQuery )
   Dim t1 As Thread = New Thread ( t1Start )
   Dim t2 As Thread = New Thread ( t2Start )

   ' cancel operation while results are coming back
   _cmd.CommandText = "SELECT * FROM orders, products"
   t1.Start ( )
   t2.Start ( )
   WaitHandle.WaitAll ( evs )
   conn.Close ( )

End Sub