winform combobox传值问题

Question

combobox绑定数据库，每次点击时总是显示最后一条记录的值，这是什么原因。程序如下：SqlConnection conn = new SqlConnection("Server=ZHANG-85CB2E418;User Id=sa;Password=123456;Database=order;");
            string commandtext = "SELECT * from Customers"; 
            SqlCommand cmd = new SqlCommand(commandtext, conn);            conn.Open();
            SqlDataReader dr = cmd.ExecuteReader();
            this.cmbCompany.Items.Clear();
            while (dr.Read())
            {
               this.cmbCompany.Items.Add(dr[1].ToString());
               this.cmbCompany.ValueMember=dr[1].ToString() ;
            }
            dr.Close();
            conn.Close();

Answer 1

楼主 dr[1].你用这个 获取数据？要用个变脸 累加 把 好像 还有dr.Read()这个 是 要.next()把我也不记得啦 好久没用这东西啦 自己在查查把 

Answer 2

while (dr.Read())
  {
  this.comboBox1.Items.Add(dr[1].ToString());
  }
  this.comboBox1.SelectedIndex = 0;

Answer 3

for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
            {
                cmbPower.Items.Add(ds.Tables[0].Rows[i]["字段"].ToString());
            }