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用.Net处理xmlHttp发送异步请求

2007-06-14 08:51 381 查看
最近正在拜读《Ajax in Action》这本书,运用书中知识,结合.net,写了这篇用.net 处理xmlHttp发送异步请求的文章。

我们要达到的目的是点击按钮,获得服务器的当前时间,aspx的html如下:

Html

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs"
Inherits="Linkedu.Web.WebWWW.Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >

<head runat="server">

<title>测试</title>

<script language="javascript" src="javascript/prototype/extras-array.js"></script>

<script language="javascript" src="javascript/xmlHttp.js"></script>

<script language="javascript" src="javascript/eventRouter.js"></script>

<script language="javascript" src="Default.js"></script>

<script language="javascript">

</script>

</head>

<body>

<form id="form1" runat="server">

用Post方式获得服务器的当前时间

<input id="btnTestPost" type="button" value="Post" />

用Get方式获得服务器的当前时间

<input id="btnTestGet" type="button" value="Get" />

<div id="divResult"></div>

</form>

</body>

</html>

要用javascript 发送xmlHttp 请求必须解决的问题是跨浏览器的支持。我们把xmlHttp的发送封装在一个javascript对象中,同时在这个对象中解决了跨浏览器支持的问题。代码如下:

xmlHttp对象

/**//*

url-loading object and a request queue built on top of it

*/

/**//* namespacing object */

var net=new Object();

net.READY_STATE_UNINITIALIZED=0;

net.READY_STATE_LOADING=1;

net.READY_STATE_LOADED=2;

net.READY_STATE_INTERACTIVE=3;

net.READY_STATE_COMPLETE=4;

/**//*--- content loader object for cross-browser requests ---*/

net.xmlHttp=function(url, onload, params, method, contentType, onerror){

this.req=null;

this.onload=onload;

this.onerror=(onerror) ? onerror : this.defaultError;

if(typeof(method) == "undefined" || method == null)

{

method = "POST";

}

this.loadXMLDoc(url, params, method, contentType);

}

net.xmlHttp.prototype.loadXMLDoc=function(url, params, method, contentType){

if (!method){

method="GET";

}

if (!contentType && method=="POST"){

contentType='application/x-www-form-urlencoded';

}

if (window.XmlHttpRequest){

this.req=new XmlHttpRequest();

} else if (window.ActiveXObject){

this.req=new ActiveXObject("Microsoft.xmlHttp");

}

if (this.req){

try{

var loader=this;

this.req.onreadystatechange=function(){

net.xmlHttp.onReadyState.call(loader);

}

this.req.open(method,url,true);

if (contentType){

this.req.setRequestHeader('Content-Type', contentType);

}

this.req.send(params);

}catch (err){

this.onerror.call(this);

}

}

}

net.xmlHttp.onReadyState=function(){

var req=this.req;

var ready=req.readyState;

if (ready==net.READY_STATE_COMPLETE){

var httpStatus=req.status;

if (httpStatus==200 || httpStatus==0){

this.onload.call(this);

}else{

this.onerror.call(this);

}

}

}

net.xmlHttp.prototype.defaultError=function(){

alert("error fetching data!"

+"/n/nreadyState:"+this.req.readyState

+"/nstatus: "+this.req.status

+"/nheaders: "+this.req.getAllResponseHeaders());

}

下面开始写发送xmlHttp请求的代码:

default.js

//全局xmlHttp对象

var cobj;

/**//* Post begin*/

//绑定Post发送xmlHttp事件到btnTestPost

function loadTestPost()

{

var iobj = document.getElementById("btnTestPost");

//btnTestPost按钮监听的绑定

var clickRouter=new jsEvent.EventRouter(iobj,"onclick");

clickRouter.addListener(btnTestPostClick);

}

function btnTestPostClick()

{ // open参数 url, onload, params, method, contentType, onerror

cobj = new net.xmlHttp("DefaultHandler.ashx",dealResult, "<T/>", "POST");

}

/**//* Post end*/

/**//* Get begin*/

//绑定Get发送xmlHttp事件到btnTestGet

function loadTestGet()

{

var iobj = document.getElementById("btnTestGet");

//btnTestGet按钮监听的绑定

var clickRouter=new jsEvent.EventRouter(iobj,"onclick");

clickRouter.addListener(btnTestGetClick);

}

function btnTestGetClick()

{ // open参数 url, onload, params, method, contentType, onerror

cobj = new net.xmlHttp("DefaultHandler.ashx?T=1",dealResult, null, "GET");

}

/**//* Get end*/

function dealResult()

{

var dobj = document.getElementById("divResult");

dobj.innerHTML = cobj.req.responseXML.text;

}

window.onload = function()

{

//绑定Post发送xmlHttp事件到btnTestPost

loadTestPost();

//绑定Get发送xmlHttp事件到btnTestGet

loadTestGet();

};

最后是.net处理xmlHttp的代码:

.net 处理xmlHttp请求

public class DefaultHandler : IHttpHandler

{

protected XmlDocument _xmlResult;

public void ProcessRequest(HttpContext context)

{

if (context.Request["T"] != null)

{//GET xmlhttp测试

context.Response.ContentType = "text/xml";

XmlDocument xmlDoc = new XmlDocument();

xmlDoc.LoadXml(string.Format(@"<time>GET:{0}</time>", System.DateTime.Now));

xmlDoc.Save(context.Response.OutputStream);

context.Response.End();

}

else

{//POST xmlhttp测试

context.Response.ContentType = "text/xml";

XmlDocument xmlDoc = new XmlDocument();

xmlDoc.Load(context.Request.InputStream);

if (xmlDoc.DocumentElement.Name == "T")

{

xmlDoc.LoadXml(string.Format(@"<time>POST:{0}</time>", System.DateTime.Now));

xmlDoc.Save(context.Response.OutputStream);

context.Response.End();

}

}

}

public bool IsReusable

{

get

{

return false;

}

}

}

来源链接:http://www.cnblogs.com/Files/laiwen/XmlHttpNet.rar/article/6080255.html
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