[/c#]
public InitFlyGrid(FlyGrid flyGrid)
{
  //...
  //....
  flyGrid.TopRowChanging += new NineRays.Windows.Forms.FlyGrid.NotifyEventHandler(flyGrid_TopRowChanging);
  flyGrid.TopRowChange += new NineRays.Windows.Forms.FlyGrid.NotifyEventHandler(flyGrid_TopRowChange);
}

private int oldTopRow = -1;
private void flyGrid_TopRowChanging(object sender)
{
  FlyGridViewPort port = sender as FlyGridViewPort;
  oldTopRow = port.TopRow;
}

private void flyGrid_TopRowChange(object sender)
{
  if (oldTopRow == 0)
  {
    FlyGridViewPort port = sender as FlyGridViewPort;
    port.TopRow = oldTopRow;
    oldTopRow = -1;
  }
}