Access the DataTable Row in GridView RowDataBound Event in ASP.Net

Then in your RowDataBound event you can get the DataRow of the DataTable as follows

protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            DataRowView dr = (DataRowView)e.Row.DataItem;
            string field1 = dr[0].ToString();
            //OR
            field1 = dr["name of field1"].ToString();
        }
}