中文版
最近做了一个向标准的html页面中读取相关信息的程式，方法已经实现，但是效率不高。仔细研究发现时XmlDocument.LoadXml方法在加载页面代码过程中耗费了过多时间。为了能简单表述问题，我将问题简化成了如下代码：
System.Xml.XmlDocument xmlDoc = new System.Xml.XmlDocument();
string xmlstr = "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\r\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\r\n<head>\r\n<meta http-equiv=\"Content-Type\" content=\"text/html; charset=gb2312\" />\r\n<title>新闻阅读</title>\r\n<link type=\"text/css\" rel=\"stylesheet\" href=\"../../NewsReaderStyle.css\" />\r\n</head>\r\n\r\n<body>\r\n<div id=\"title\">猪流感来临 “宅男”成老公上上选？</div>\r\n<div id=\"status\">2009年05月03日 <span id=\"source\">武汉晚报</span></div>\r\n<div id=\"content\">猪流感来临 “宅男”成老公上上选？</div>\r\n</body>\r\n</html>\r\n";
xmlDoc.LoadXml(xmlstr.Replace("\r\n", string.Empty));
Response.Write(xmlDoc.GetElementById("content").InnerXml);
结果在LoadXml方法那里停留了大概6秒的时间。对于一个文件操作超过1秒就已经很是问题了，6秒就意味着该方案无法通过。而且不管我如何简化html字符串，需要加载的时间仍旧是6秒左右。对于msdn上的例子doc.LoadXml("<item><name>wrench</name></item>");运行的时间的确很短，但是我想问，为何前者耗时6秒呢？LoadXml本身的机制如何？
English Version
Recently,I do a programe of fetching informations from standard html page,and I have done that. Unfortunately,the code runs inefficiently。I fount the touble is that it's cost too much time on the method XmlDocument.LoadXml while loading the html code。I show a simple code below in order to make the problem clearly.
System.Xml.XmlDocument xmlDoc = new System.Xml.XmlDocument();
string xmlstr = "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\r\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\r\n<head>\r\n<meta http-equiv=\"Content-Type\" content=\"text/html; charset=gb2312\" />\r\n<title>新闻阅读</title>\r\n<link type=\"text/css\" rel=\"stylesheet\" href=\"../../NewsReaderStyle.css\" />\r\n</head>\r\n\r\n<body>\r\n<div id=\"title\">猪流感来临 “宅男”成老公上上选？</div>\r\n<div id=\"status\">2009年05月03日 <span id=\"source\">武汉晚报</span></div>\r\n<div id=\"content\">猪流感来临 “宅男”成老公上上选？</div>\r\n</body>\r\n</html>\r\n";
xmlDoc.LoadXml(xmlstr.Replace("\r\n", string.Empty));
Response.Write(xmlDoc.GetElementById("content").InnerXml);
In surprise, the code spend 6 seconds in the method LoadXml and it's too long to wait for a file operation. In another way, I did try the example of msdn [doc.LoadXml(
"<item><name>wrench</name></item>");], it runs rapidly. So what's going on? Who can tell me how to do!
