js|xml|异步
1.新建一个vs2003的web工程,取名为XMLTest
2.将工程目录下的WebForm1.aspx中内容全部删除，只留下顶部的一条语句：
<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="XMLTest.WebForm1" %>
3.修改WebForm1.aspx.cs中内容，在Page_Load中加入:
XmlDocument doc=new XmlDocument();
String xmlfile=string.Empty;
xmlfile=Context.Request.PhysicalApplicationPath+(Request.QueryString["sel"].ToString()=="xml"?"\\hello.xml":"\\hello.xsl");
doc.Load(xmlfile);
Response.Write(doc.InnerXml);
4.在工程根目录下新增test.htm,并设为工程首页:
<html>
<head>
<title></title>
</head>
<body>
<div id="resTree"></div>
<FONT face="宋体"></FONT><input type="button" value="执行" ><BR>
<script language="JScript">
var srcTree,xsltTree,xt;
var http_request = false;
function GetXml()
{
srcTree = new ActiveXObject("Msxml2.FreeThreadedDOMDocument");
srcTree.async=false;
xsltTree= new ActiveXObject("Msxml2.FreeThreadedDOMDocument");
xsltTree.async = false;
xt=new ActiveXObject("MSXML2.XSLTemplate");
resTree.innerHTML="";
makeRequest("WebForm1.aspx?sel=xml",GetXml_CB);
}
function makeRequest(url,callback) {
http_request = false;
if (window.XMLHttpRequest) { // Mozilla, Safari,...
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType) {
http_request.overrideMimeType('text/xml');
}
} else if (window.ActiveXObject) { // IE
try {
http_request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
http_request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {}
}
}
if (!http_request) {
alert('Giving up :( Cannot create an XMLHTTP instance');
return false;
}
http_request.onreadystatechange = callback;
http_request.open('GET', url, true);
http_request.send(null);
}
function GetXml_CB() {
if (http_request.readyState == 4) {
if (http_request.status == 200) {
srcTree.loadXML(http_request.responseText);
makeRequest("WebForm1.aspx?sel=xsl",GetXsl_CB);
} else {
alert('There was a problem with the request.');
}
}
}
function GetXsl_CB(){
if (http_request.readyState == 4) {
if (http_request.status == 200) {
xsltTree.loadXML(http_request.responseText);
xt.stylesheet=xsltTree;
var proc=xt.createProcessor();
proc.input=srcTree;
proc.transform();
resTree.innerHTML=proc.output;
} else {
alert('There was a problem with the request.');
}
}
}
function makeRequest(url,callback) {
http_request = false;
if (window.XMLHttpRequest) { // Mozilla, Safari,...
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType) {
http_request.overrideMimeType('text/xml');
}
} else if (window.ActiveXObject) { // IE
try {
http_request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
http_request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {}
}
}
if (!http_request) {
alert('Giving up :( Cannot create an XMLHTTP instance');
return false;
}
http_request.onreadystatechange = callback;
http_request.open('GET', url, true);
http_request.send(null);
}
</script>
</body>
</html>
5.运行工程，看看效果吧!
hello.xml(注意:我的xml文档中并没有指定对应的xsl解析文件名)
<?xml version='1.0'?>
<breakfast-menu>
<food>
<name>Belgian Waffles</name>
<price>$5.95</price>
<description>Two of our famous Belgian Waffles
with plenty of real maple syrup.</description>
<calories>650</calories>
</food>
<food>
<name>Strawberry Belgian Waffles</name>
<price>$7.95</price>
<description>Light Belgian waffles covered with
strawberries and whipped cream.</description>
<calories>900</calories>
</food>
<food>
<name>Berry-Berry Belgian Waffles</name>
<price>$8.95</price>
<description>Light Belgian waffles covered
with an assortment of fresh berries
and whipped cream.</description>
<calories>900</calories>
</food>
<food>
<name>French Toast</name>
<price>$4.50</price>
<description>Thick slices made from our homemade
sourdough bread.</description>
<calories>600</calories>
</food>
<food>
<name>Homestyle Breakfast</name>
<price>$6.95</price>
<description>Two eggs, bacon or sausage, toast,
and our ever-popular hash browns.</description>
<calories>950</calories>
</food>
</breakfast-menu>
hello.xsl
<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/breakfast-menu">
<xsl:for-each select="food">
<DIV STYLE="background-color:teal; color:white; padding:4px">
<SPAN STYLE="font-weight:bold; color:white"><xsl:value-of select="name"/></SPAN>
至 <xsl:value-of select="price"/>
</DIV>
<DIV STYLE="margin-left:20px; margin-bottom:1em; font-size:10pt">
<xsl:value-of select="description"/>
<SPAN STYLE="font-style:italic">
<xsl:value-of select="calories"/> 嘿嘿
</SPAN>
</DIV>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
xml文档只有纯粹的数据，如果需要显示到html页面中的话，一般需要使用定制的xsl文档来解析，或者手工通过js来读取xml中的值显示到html中的dom树中，当使用xsl文档来解析时，相应的xml文档中必须指定对应的xsl文档才能正常显示，但当有些程序动态输出xml文档时，并没有指定相应的xsl文档，这时就必须通过其它途径来加载相应的xsl文档来解析，当然，在服务器端输出xml文档时，通过一些xml api也可以实现，我这儿描述的是通过js来实现的一种方式。用这种方式的话，就抛开了服务器平台的限制，服务器端只需要输出相应的xml文档(.net/j2ee都可以)，并且将对应的xsl文档输出给客户端（可以输出流或直接在客户端加载xsl文档)。
这里有几个需要注意的地方，我们一般是使用Msxml2.Document组件来加载xml文档的，但当动态使用xsl解析xml文档时，必须使用Msxml2.FreeThreadedDOMDocument这种自由线程的组件，同时使用MSXML2.XSLTemplate模板组件来加载xml,xsl数据，通过MSXML2.XSLTemplate的transform方法，就可以动态的用xsl来解析xml数据了,另外，IE5开始，系统默认的xml组件是msxml2，如果需要使用更新的msxml组件需要安装更新的msxml组件包，并指定新的名称，例如Msxml2.FreeThreadedDOMDocument.4.0，现在最新的msxml组件是6.0beta，可在M$网站下载。
演示：http://www.21cz.cn/xmltest/test.htm
xml文件查看：http://www.21cz.cn/xmltest/hello.xml
xsl文件查看：http://www.21cz.cn/xmltest/hello.xsl