<div>        <asp:ListBox ID="ListBox1" runat="server"></asp:ListBox>  <br />        <asp:Button ID="Button1" runat="server" Text="Get Selected Values" OnClick="Button1_Click" />    </div>

 protected void Page_Load(object sender, EventArgs e)        {            if (!IsPostBack)            {                   //填充数据                    DataTable dt = new DataTable();                    dt.Columns.Add(new DataColumn() { ColumnName = "Id", DataType = typeof(int) });                    dt.Columns.Add(new DataColumn() { ColumnName = "Name", DataType = typeof(string) });                    dt.Rows.Add(1, "Scott");                    dt.Rows.Add(2, "John");                    dt.Rows.Add(3, "Tom");                    dt.Rows.Add(4, "Ross");                       ListBox1.DataValueField = "Id";                    ListBox1.DataTextField = "Name";                    ListBox1.DataSource = dt;                    ListBox1.DataBind();            }        }        protected void Button1_Click(object sender, EventArgs e)        {            int id = int.Parse(ListBox1.SelectedItem.Value);            Response.Write(id);        }