Ajax笔记

1，创建XMLHttpRequest对象
xmlhttp=new XMLHttpRequest(); -- IE7+, Firefox, Chrome, Safari, and Opera
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); -- IE5, IE6

2，将XML文本解析为 xml doc对象：
[b]Internet Explorer uses the loadXML() method to parse an XML string, while other browsers use the DOMParser object.[/b]
if (window.DOMParser) // firefox
{
parser=new DOMParser();
xmlDoc=parser.parseFromString(txt,"text/xml");
}
else // Internet Explorer
{
xmlDoc=new ActiveXObject("Microsoft.XMLDOM");
xmlDoc.async=false;
xmlDoc.loadXML(txt);
}
读取XML文件为 xml doc对象：
if (window.DOMParser) // firefox
{
xmlDoc=document.implementation.createDocument("","",null);
xmlDoc.async="false";
xmlDoc.load("xxx.xml");
}
else // Internet Explorer
{
xmlDoc=new ActiveXObject("Microsoft.XMLDOM");
xmlDoc.async="false";
xmlDoc.load("xxx.xml");
}