dropdownlist 、listbox 与 panel的使用

panel(对象容器)：向容器中添加控件   Panel.Controls.Add(new 控件()）；


listbox 中添加items
 一个 dropdownlist 控制listbox示例：
 protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        this.ListBox1.Items.Clear();
        SqlConnection con = depart.Class1.createconnection();
        con.Open();
        SqlCommand cmd = new SqlCommand("select * from emp where did=" + this.DropDownList1.SelectedValue.ToString(), con);
        SqlDataReader chsdr = cmd.ExecuteReader();
        while (chsdr.Read())
        {

            this.ListBox1.Items.Add(new ListItem(chsdr.GetString(1), chsdr.GetInt32(0).ToString()));
           
        }
        chsdr.Close();
        con.Close();
    }


吃饭了...................