javascript读取xml实现javascript分页

2019-11-20 21:28:28

字体：大中小

来源：转载

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<!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>