Quick ADO.Net Tip

If you need to stop a datareader in the middle, instead of at the end, you have to call cancel on the command object. Calling the Close() method will result in a timeout exception.

using (SqlCommand cmd = new SqlCommand(sql, conn))
{
          XmlReader reader = cmd.ExecuteXmlReader();
          reader.Read();

while (!reader.EOF)
{
            if (this.Cancel)
            {
                cmd.Cancel();
                reader.Close():
                break;
            }
            holder = reader.ReadOuterXml();
}

}