asp.net 2.0中用 ICallbackEventHandler 实现无刷新联动

vs2005beta2 中通过

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">

<title>Untitled Page</title>

function ClientCallback(result, context)

{

var dropdown2 = document.forms[0].elements['DropDownList2'];

dropdown2.innerHTML= "";

var rows = result.split('|');

alert(result.length);

for (var i = 0; i < rows.length - 1; ++i)

{

var values = rows[i]

var option = document.createElement("OPTION");

option.value = values;

option.innerHTML = values;

dropdown2.appendChild(option);

}

function GetOrders(arg, context)

{

<%= callBack %> ;

}

</script>

</head>

<body>

<div>

<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:pubsConnectionString2 %>" SelectCommand="SELECT [au_id], [au_lname], [au_fname] FROM [authors]">

</asp:SqlDataSource>

<asp:DropDownList ID="DropDownList1" runat="server">

</asp:DropDownList>

<asp:DropDownList ID="DropDownList2" runat="server">

</asp:DropDownList></div>

</form>

</body>

</html>

using System;

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;

using System.Data.SqlClient;

public partial class Default2 : System.Web.UI.Page, System.Web.UI.ICallbackEventHandler

{

protected void Page_Load(object sender, EventArgs e)

{

if (!this.IsPostBack)

{

this.DropDownList1.DataSource = this.SqlDataSource1;

this.DropDownList1.DataTextField = "au_lname";

this.DropDownList1.DataValueField = "au_id";

this.DropDownList1.DataBind();

this.DropDownList1.Attributes.Add("onchange", "GetOrders(this.options[this.selectedIndex].value,'bbbbb');");

}

protected String callBack

{

get

{

return this.ClientScript.GetCallbackEventReference(this, "arg", "ClientCallback", "context");

}

public string RaiseCallbackEvent(string eventArgument)

{

DataSet ds = new DataSet();

SqlConnection cnn=new SqlConnection ("Data Source=JKDL-PORTAL;Initial Catalog=pubs;Persist Security Info=True;User ID=sa;Password=111" );

SqlDataAdapter da = new SqlDataAdapter("select titles.title_id,title from titles inner join titleauthor on titleauthor.title_id = titles.title_id where au_id = '" + eventArgument + "'", cnn);

cnn.Open ();

da.Fill(ds);

System.Text.StringBuilder str = new System.Text.StringBuilder();

foreach (DataRow dr in ds.Tables[0].Rows)

{

str.Append(dr["title"]);

str.Append("|");

}

return str.ToString ();

}

呵..... 越来越好了....

参考
http://www.extremeexperts.com/Net/Articles/ClientCallbacksinASPNETWhidbey.aspx