原文发布时间为：2008-07-29 —— 来源于本人的百度文章 [由搬家工具导入]

using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class Default3 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            ArrayList name = new ArrayList();
            name.Add("lily");
            name.Add("lucy");
            name.Add("lilei");

            DropDownList1.DataSource = name;
            DropDownList1.DataBind();
        }

    }
    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        switch (DropDownList1.SelectedValue)
        {
            case "lily":
                Label1.Text = "lily a";
                break;
            case "lucy":
                Label1.Text = "lucy b";
                break;
            case "lilei":
                Label1.Text = "lilei c";
                break;
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string add = TextBox1.Text;
        DropDownList4.Items.Add(add);
    }
}

net3：DropDownList的动态绑定