How to FillCombo in C#

This code snippet will tell you how to fillcombo in C# programming.

DataTable _comdt = new DataTable();
_comdt = fillcombo();
if (_comdt.Rows.Count > 0)
{
    int i;
    for (i = 0; i < _comdt.Rows.Count; i++)
    {
        Dll_name.Items.Add(_comdt.Rows[i].ItemArray[0]);
    }
}


public DataTable fillcombo()
{
    DataTable _comdt = new DataTable();
    string querystring = "select [Company_name] from Company_Mst order by [ID] DESC;";
    OleDbConnection _objcon = conection();
    OleDbCommand cmd;
    OleDbDataAdapter _objda = new OleDbDataAdapter(querystring, _objcon);
    _objcon.Close();
    _objcon.Open();
    _objda.Fill(_comdt);
    return _comdt;
}