ComboBox，从类中提取数据

Question

我不能:(请帮帮我:(

表格方：

    {
        conn.Open();
       SqlCommand cmd = new SqlCommand
        ("select BusinessEntityID from Person.Person order by'BusinessEntityID' ASC", conn);
        SqlDataReader dr = cmd.ExecuteReader();
        while (dr.Read())
        {
            comboBox1.Items.Add(dr["BusinessEntityID"]);
        }
        conn.Close();
    }

这个，我应该在课堂上写。我需要在表格旁边打电话