[GridView] 마우스 클릭 으로 Row 다중선택

private void GridView_MouseDown(object sender, MouseEventArgs e)
{
	GridHitInfo gridHI = (sender as GridView).CalcHitInfo(e.Location);
	if (gridHI != null && gridHI.InRowCell)
	{
		if ((sender as GridView).IsRowSelected(gridHI.RowHandle))
		{
			(sender as GridView).UnselectRow(gridHI.RowHandle);
		}
		else
		{
			(sender as GridView).SelectRow(gridHI.RowHandle);
		}
		DXMouseEventArgs.GetMouseArgs(e).Handled = true;
	}
}