出处：http://www.smallrain.net/study_show.asp?id=703
<div id="Error"></div>
<div id="State"></div>
<div id="DownloadEnd"></div>
<Script Language="JavaScript">
<!--
// more javascript from http://www.smallrain.net
function Ajax(OnError,OnState,OnDownloadEnd)
{
// 错误字符串
this.ErrorStr = null;
// 错误事件驱动,当发生错误时触发
this.OnError = OnError;
// 状态事件驱动,当状态改变时触发
this.OnState = OnState;
// 完成事件驱动,当类操作完成时触发
this.OnDownloadEnd = OnDownloadEnd;
// XMLHTTP 发送数据类型 GET 或 POST
this.method = "GET";
// 将要获取的URL地址
this.URL = null;
// 指定同步或异步读取方式(true 为异步,false 为同步)
this.sync = true;
// 当method 为 POST 时 所要发送的数据
this.PostData = null
// 返回读取完成后的数据
this.RetData = null;
// 创建XMLHTTP对像
this.HttpObj = this.createXMLHttpRequest();
if(this.HttpObj == null)
{
// 对像创建失败时中止运行
return;
}
var Obj = this;
// 调用事件检测
this.HttpObj.onreadystatechange = function()
{
Ajax.handleStateChange(Obj);
}
}
// UTF 转入 GB (by:Rimifon)
Ajax.prototype.UTFTOGB = function(strBody)
{
var Rec=new ActiveXObject("ADODB.RecordSet");
Rec.Fields.Append("DDD",201,1);
Rec.Open();
Rec.AddNew();
Rec(0).AppendChunk(strBody);
Rec.Update();
var HTML=Rec(0).Value;
Rec.Close();
delete Rec;
return(HTML);
}
// 创建XMLHTTP对像
Ajax.prototype.createXMLHttpRequest = function()
{
if (window.XMLHttpRequest)
{
//Mozilla 浏览器
return new XMLHttpRequest();
}
else if (window.ActiveXObject)
{
var msxmls = new Array('Msxml2.XMLHTTP.5.0','Msxml2.XMLHTTP.4.0','Msxml2.XMLHTTP.3.0','Msxml2.XMLHTTP','Microsoft.XMLHTTP');
for (var i = 0; i < msxmls.length; i++)
{
try
{
return new ActiveXObject(msxmls[i]);
}catch (e){}
}
}
this.ErrorStr = "你的浏览器不支持XMLHttpRequest对象．"
if(this.OnError)
{
this.OnError(this.ErrorStr);
}
return null;
}
// 发送HTTP请求
Ajax.prototype.send = function()
{
if (this.HttpObj !== null)
{
this.URL = this.URL + "?t=" + new Date().getTime();
this.HttpObj.open(this.method, this.URL, this.sync);
if(this.method.toLocaleUpperCase() == "GET")
{
this.HttpObj.send(null);
}
else if(this.method.toLocaleUpperCase() == "POST")
{
this.HttpObj.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
this.HttpObj.send(this.PostData);
}
else
{
this.ErrorStr = "错误的[method]命令．"
if(this.OnError)
{
this.OnError(this.ErrorStr);
}
return;
}
if (this.HttpObj.readyState == 4)
{
// 判断对象状态
if (this.HttpObj.status == 200)
{
this.RetData = this.UTFTOGB(this.HttpObj.responseBody);
if(this.OnDownloadEnd)
{
this.OnDownloadEnd(this.RetData);
}
return;
}
else
{
this.ErrorStr = "您所请求的页面有异常．"
if(this.OnError)
{
this.OnError(this.ErrorStr);
}
return;
}
}
}
}
// 事件检测
Ajax.handleStateChange = function(Obj)
{
if(Obj.OnState)
{
Obj.OnState(Obj.HttpObj.readyState);
}
if (Obj.HttpObj.readyState == 4)
{
// 判断对象状态
if (Obj.HttpObj.status == 200)
{
Obj.RetData = Obj.UTFTOGB(Obj.HttpObj.responseBody);
if(Obj.OnDownloadEnd)
{
Obj.OnDownloadEnd(Obj.RetData);
}
return;
}
else
{
Obj.ErrorStr = "您所请求的页面有异常．"
if(Obj.OnError)
{
Obj.OnError(Obj.ErrorStr);
}
return;
}
}
}
// 错误回调事件函数
function EventError(strValue)
{
document.getElementById("Error").innerHTML = strValue;
}
// 状态回调事件函数
function EventState(strValue)
{
var strState = null;
switch (strValue)
{
case 0:
strState = "未初始化...";
break;
case 1:
strState = "开始读取数据...";
break;
case 2:
strState = "读取数据...";
break;
case 3:
strState = "读取数据中...";
break;
case 4:
strState = "读取完成...";
break;
default:
strState = "未初始化...";
break;
}
document.getElementById("State").innerHTML = strState;
}
// 完成回调事件函数
function EventDownloadEnd(strValue)
{
document.getElementById("DownloadEnd").innerHTML = strValue;
}
// 初始化Ajax对像,引入事件回调函数
var A1 = new Ajax(EventError,EventState,EventDownloadEnd);
// 指定method数据发送类型
A1.method = "GET";
// 指定URL地址
A1.URL = "http://www.smallrain.net/help.htm"
// 指定为异步处理
A1.sync = true;
//发送请求
A1.send();
//-->
</Script>