private void button1_Click(object sender, EventArgs e)        {            SqlConnection conn = new SqlConnection();            conn.ConnectionString = "Data Source=.;Password=123456;User ID=sa;Initial Catalog=guo;database=guo";            conn.Open();            SqlCommand cmd = new SqlCommand();            cmd.Connection = conn;            cmd.CommandText = "select * from dbo.[user]";            SqlDataReader reader = cmd.ExecuteReader();                        while (reader.Read())            {                Object[] values = new Object[reader.FieldCount];                int nCount = reader.GetValues(values);                for (int i = 0; i != nCount; ++i)                    listBox1.Items.Add(values[i]);            }                //             while (reader.Read())                //             {                //                     listBox1.Items.Add(reader[1]);                //             }                conn.Close();        }