动态添加ComboBox，并在触发change时间后取出相应的值

private void button1_Click(object sender, EventArgs e)
  {
   ComboBox cbo = new ComboBox();
   cbo.Dock = DockStyle.Fill;
   cbo.Name = "comb";
   cbo.DropDownStyle = ComboBoxStyle.DropDownList;
   this.tableLayoutPanel1.Controls.Remove(this.textBox1);
   this.tableLayoutPanel1.Controls.Add(cbo, 2, 0);
   DataTable dt = FillTable();
   cbo.DataSource = dt;
   cbo.DisplayMember = "name";
   cbo.ValueMember = "id";
   cbo.SelectedValue = Convert.ToInt32(dt.Rows[0][0]);
   cbo.SelectedIndexChanged += new EventHandler(cbo_SelectedIndexChanged);
   //cbo.SelectedValueChanged += new EventHandler(cbo_SelectedValueChanged);
   aa = cbo.Text.ToString();
  }

  public DataTable CreateTable()
  {
   DataTable dt = new DataTable();
   dt.Columns.Add("id",typeof(int));
   dt.Columns.Add("name",typeof(string));
   return dt;
  }
  public DataTable FillTable()
  {
   DataTable dt = CreateTable();
   for (int i = 0; i < 4; i++)
   {
    DataRow dr = dt.NewRow();
    dr["id"] = i+2;
    dr["name"] = i.ToString() + "9";
    dt.Rows.Add(dr);
   }
   return dt;
  }
  void cbo_SelectedIndexChanged(object sender, EventArgs e)
  {
   Control[] controlList = this.Controls.Find("comb", true);
   foreach (Control control in controlList)
   {
    //MessageBox.Show(((ComboBox)control).Text);
    MessageBox.Show(((ComboBox)control).SelectedValue.ToString());
   }

   label1.Text = "1111成功！";
  }