caricare combo c#

[ussfabio]

ragazzi non riesco a caricare la combo....come faccio?


SqlConnection conn = DBManager.getConnection();
conn.Open();

string strQuery = "select TreNumTreno from treni";
SqlCommand myCommand = new SqlCommand(strQuery);
myCommand.Connection = conn;
object ret = myCommand.ExecuteScalar();
SqlDataReader reader = myCommand.ExecuteReader (CommandBehavior.CloseConnection);


cboTreni.DataSource = myCommand.ExecuteReader();
cboTreni.DataBind();

[Cartman]

cboTreni.DataSource = reader;