javascript读取xml实现javascript分页

  

复制代码 代码如下:

  <!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>

  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

  <title>读取Xml并分页</title>

  </head>

  <body >

  <div id="gao">

  </div>

  <div>

  <table align="center">

  <tr>

  <td><input type="button" name="prev" id="prev" value="上一页"  onclick="showPage('false')"><input type="button" id="next" name="next" value="下一页" onclick="showPage('true')"> </td>

  </tr>

  </table>

  </div>

  <script type="text/javascript">

  function LoadXML(url)

  {

  var xmlDoc;

  if(window.ActiveXObject)

  {

  xmlDoc=new ActiveXObject("Microsoft.XMLDOM");

  xmlDoc.async="false";

  xmlDoc.load(url);

  }else if(document.implementation&&document.implementation.createDocument)

  {

  xmlDoc=document.implementation.createDocument("","",null);

  xmlDoc.async=false;

  xmlDoc.load(url);

  }else

  {

  alert("You browser cannot handle this script!");

  }

  return xmlDoc;

  }

  var xmlDoc=LoadXML("student.xml");

  var students=xmlDoc.getElementsByTagName("student");

  var stuLength=students.length;

  var currentPage=0;

  var pageSize=2;

  var maxPage=Math.ceil(stuLength/pageSize);

  function showPage(page)

  {

  var mytable=document.getElementsByTagName("table")[1];

  if(mytable) document.body.removeChild(mytable);

  var table=document.createElement("table");

  table.setAttribute("id","mytable");

  table.setAttribute("width","600");

  table.setAttribute("border","1");

  document.body.appendChild(table);

  var header=table.createTHead();

  var headerrow=header.insertRow(0);

  headerrow.insertCell(0).appendChild(document.createTextNode("姓名"));

  headerrow.insertCell(1).appendChild(document.createTextNode("学校"));

  headerrow.insertCell(2).appendChild(document.createTextNode("成绩"))

  if(page=="true")

  currentPage++;

  else

  currentPage--;

  if(currentPage>=maxPage) currentPage=maxPage;

  else if(currentPage<=0) currentPage=1;

  var start=(currentPage-1)*pageSize;

  var end=currentPage*pageSize-1;

  for(var i=start;i<=end;i++)

  {

  var e=students[i];

  var name=e.getAttribute("name");

  var school=e.getElementsByTagName("school")[0].firstChild.data;

  var grade=e.getElementsByTagName("grade")[0].firstChild.data;

  var row=table.insertRow(i%pageSize+1);

  row.insertCell(0).appendChild(document.createTextNode(name));

  row.insertCell(1).appendChild(document.createTextNode(school));

  row.insertCell(2).appendChild(document.createTextNode(school));

  }

  }

  showPage("true");

  </script>

  </body>

  </html>

  在编写过程过,涉及到代码的处理上,由于我最初,将javascript代码放在了head标签里面,结果导致document.body对象为空!

  我们都知道,javascript在执行的时候,页面会暂定加载而去执行html代码,所以当js代码放在head标签中的时候,html页面还没有执行到body,故而产生了错误!

  后来将js代码,放在了body的尾部,这样,就能够正确引用到body对象了!

  同时,在大型网站架构中,也是提高页面加载速度的一种方式!页面首页加载html标签内容,到页面最后,在执行js代码,能在很大程度上提升网页打开速度,提升用户体验!

  另外的student.xml内容是

  

复制代码 代码如下:

  <?xml version="1.0" encoding="utf-8"?>

  <students>

  <student name="gaoxing">

  <school>西北大学1</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北大学2</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北大3学</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北大学4</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北大5学</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北大6学</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北大7学</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北8大学</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北9大学</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北10大学</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北大学</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北大学</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北大学</school>

  <grade>76</grade>

  </student>

  <student name="gaoxing">

  <school>西北大学</school>

  <grade>76</grade>

  </student>

  </students>