have a look at :
http://www.devexpress.com/Support/Center/p/Q290537.aspx[
^]
OR
try in the following way :
string strConn = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
string strProvider = ConfigurationManager.ConnectionStrings["ConnectionString"].ProviderName;
SqlDataSource ds = new SqlDataSource(strProvider, strConn);
ds.SelectCommand = "SELECT * FROM rammekategori";
Then i bind the SqlDataSource to a GridView:
GridView1.DataSource = ds;
GridView1.DataBind();