A. 怎么爬取网页的动态内容,很多都是js动态生
抓取动态页面有两种常用的方法,一是通过javaScript逆向工程获取动态数据接口(真实的访问路径),另一种是利用selenium库模拟真实浏览器,获取JavaScript渲染后的内容。但selenium库用起来比较繁琐,抓取速度相对较慢,所以第一种方法日常使用较多。
B. 只用js如何实现表格内容的动态修改
<body>
<tableid='test'>//定义一个table
<tr>
<td></td><td></td>
</tr>
</table>
<script>
vartb=document.getElementById('test');//获取表格的dom节点
vartd=tb.rows[0].cells[0];//获取0行0列的td单元格
td.innerHTML='222';//动态修改表格的内容为222
</script>
</body>
思路:
1、获取表格的dom节点
2、通过rows和cells定位td单元格
3、通过修改innerHTML
JS实现动态表格的新增,修改,删除操作
一、相关JS函数
function setParamslist() {
var tab = document.getElementById("tab");
//表格行数
var rows = tab.rows.length ;
//表格列数
var cells = tab.rows.item(0).cells.length ;
//alert("行数"+rows+"列数"+cells);
var rowData = "";
for(var i=1;i<rows;i++) {
var cellsData = new Array();
for(var j=0;j<cells-1;j++) {
cellsData.push(tab.rows[i].cells[j].innerText);
}
rowData = rowData + "|" + cellsData;
}
document.getElementById("paramslist").value = rowData;
}
//打开相关新增应用参数界面
function openAppParamsPage() {
var param = new Object();
//这个参数一定要传。
param.win = window;
param.id = 100;
param.name = "test";
param.birthday = new Date();
var result = window.showModalDialog("addParamsItem","dialogWidth:500px;dialogHeight:600px;dialogLeft:200px;dialogTop=200px");
//var temp = document.getElementById("paramslist").value;
//document.getElementById("paramslist").value = temp + result;
addSort(result);
}
// 增加应用参数函数
function addSort(data) {
var name = data;
if(name == ""||name==undefined ) {
return;
}
console.log(data);
var params = data.split(",");
var paramName = params[0];
var paramCode = params[1];
var paramValue = params[2];
var row = document.createElement("tr");
row.setAttribute("id", paramCode);
var cell = document.createElement("td");
cell.appendChild(document.createTextNode(paramName));
row.appendChild(cell);
cell = document.createElement("td");
cell.appendChild(document.createTextNode(paramCode));
row.appendChild(cell);
cell = document.createElement("td");
cell.appendChild(document.createTextNode(paramValue));
row.appendChild(cell);
var deleteButton = document.createElement("input");
deleteButton.setAttribute("type", "button");
deleteButton.setAttribute("value", "删除");
deleteButton.onclick = function () { deleteSort(paramCode); };
cell = document.createElement("td");
cell.appendChild(deleteButton);
row.appendChild(cell);
document.getElementById("sortList").appendChild(row);
}
// 删除应用参数函数
function deleteSort(id) {
if (id!=null){
var rowToDelete = document.getElementById(id);
var sortList = document.getElementById("sortList");
sortList.removeChild(rowToDelete);
}
}
二、弹出框页面,新增或者修改参数,并回写相关数据。
<!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>新增应用</title>
<#include "/views/head.html"/>
</head>
<body>
<div class="body-box">
<div class="clear"></div>
<form >
<table width="100%" cellspacing="1" cellpadding="2" border="0"class="pn-ftable">
<tr>
<td>参数名称:</td>
<td class="pn-fcontent"><input type="text" maxlength="20" class="" required="true" id="paramName" name="paramName"/></td>
</tr>
<tr>
<td>参数编码:</td>
<td class="pn-fcontent"><input type="text" maxlength="20" class="" required="true" id="paramCode" name="paramCode" required="true" /></td>
</tr>
<tr>
<td>参数值:</td>
<td class="pn-fcontent"><input type="text" maxlength="20" class="" required="true" id="paramValue" name="paramValue" required="true" /></td>
</tr>
<tr>
<td align="center" colspan="4">
<input type="submit" value="保存" onclick="returnResult();"/>
<input type="button" value="返回" onclick="closeWindow();"/>
</td>
</tr>
</table>
</form>
</div>
</body>
</html>
<script type="text/javascript">
//直接关闭窗口
function closeWindow() {
window.close();
}
//获取值,组装后返回
function returnResult() {
if(!$('form').valid())
return;
var paramName = document.getElementById("paramName");
var paramCode = document.getElementById("paramCode");
var paramValue = document.getElementById("paramValue");
//alert("value is " + paramName.value + "," + paramCode.value + "," + paramValue.value);
var result = paramName.value + "," + paramCode.value + "," + paramValue.value;
window.returnValue = result;
window.close();
}
</script>
C. 如何用python爬取js动态生成内容的页面
抓取js动态生成的内容的页面有两种基本的解决方案
1用dryscrape库动态抓取页面
js脚本是通过浏览器来执行并返回信息的,所以,抓取js执行后的页面,一个最直接的方式就是用python模拟浏览器的行为。WebKit 是一个开源的浏览器引擎,python提供了许多库可以调用这个引擎,dryscrape便是其中之一,它调用webkit引擎来处理包含js等的网页!
2 selenium web测试框架
selenium是一个web测试框架,它允许调用本地的浏览器引擎发送网页请求,所以,它同样可以实现抓取页面的要求。
D. js动态添加内容
第一个:a,创建一个img元素,然后添加到div节点下面。
第二个:innerHTML , 直接用HTML代码加入。
<!--
varimg=document_createElement_x('img'),
fff=document.getElementByIdx_x('aaa');
img.setAttribute('src','http://www.blueidea.com/articleimg/bbsimg/topic5.gif');
img.style.position='absolute';
img.style.left=fff.offsetLeft+20+'px';
img.style.top=fff.offsetTop+30+'px';
fff.a(img);
//-->
<script>
onload=functionf(){
document.getElementByIdx_x_x("insert").innerHTML='<imgsrc="new_banner.jpg"height="100"width="100"/>';
}
</script>
<divid="insert"></div>
E. js动态显示文本内容
<?php
$filename="1.txt";
$filename2="2.txt";
$handle=fopen($filename,"r");
$handle2=fopen($filename2,"r");
//通过filesize获得文件大小,将整个文件一下子读到一个字符串中
$contents=fread($handle,filesize($filename));
$contents2=fread($handle2,filesize($filename2));
fclose($handle);
var_mp($contents);
var_mp($contents2);
echo'<br>';
echo"$contents-$contents2*2";
echo'<br>';
echo$contents-$contents2*2;
?>
你可以将这两个数值传递到前端用js计算. 反正已经知道了结果.
至于实时动态显示最新的结果. 如果页面不刷新也可以获取, 那么就用ajax做或者websocket做.
F. 只用js如何实现表格内容的动态修改
<body>
<tableid='test'>//定义一个table
<tr>
<td></td><td></td>
</tr>
</table>
<script>
vartb=document.getElementById('test');//获取表格的dom节点
vartd=tb.rows[0].cells[0];//获取0行0列的td单元格
td.innerHTML='222';//动态修改表格的内容为222
</script>
</body>
思路:
1、获取表格的dom节点
2、通过rows和cells定位td单元格
3、通过修改innerHTML
JS实现动态表格的新增,修改,删除操作
一、相关JS函数
function setParamslist() {
var tab = document.getElementById("tab");
//表格行数
var rows = tab.rows.length ;
//表格列数
var cells = tab.rows.item(0).cells.length ;
//alert("行数"+rows+"列数"+cells);
var rowData = "";
for(var i=1;i<rows;i++) {
var cellsData = new Array();
for(var j=0;j<cells-1;j++) {
cellsData.push(tab.rows[i].cells[j].innerText);
}
rowData = rowData + "|" + cellsData;
}
document.getElementById("paramslist").value = rowData;
}
//打开相关新增应用参数界面
function openAppParamsPage() {
var param = new Object();
//这个参数一定要传。
param.win = window;
param.id = 100;
param.name = "test";
param.birthday = new Date();
var result = window.showModalDialog("addParamsItem","dialogWidth:500px;dialogHeight:600px;dialogLeft:200px;dialogTop=200px");
//var temp = document.getElementById("paramslist").value;
//document.getElementById("paramslist").value = temp + result;
addSort(result);
}
// 增加应用参数函数
function addSort(data) {
var name = data;
if(name == ""||name==undefined ) {
return;
}
console.log(data);
var params = data.split(",");
var paramName = params[0];
var paramCode = params[1];
var paramValue = params[2];
var row = document.createElement("tr");
row.setAttribute("id", paramCode);
var cell = document.createElement("td");
cell.appendChild(document.createTextNode(paramName));
row.appendChild(cell);
cell = document.createElement("td");
cell.appendChild(document.createTextNode(paramCode));
row.appendChild(cell);
cell = document.createElement("td");
cell.appendChild(document.createTextNode(paramValue));
row.appendChild(cell);
var deleteButton = document.createElement("input");
deleteButton.setAttribute("type", "button");
deleteButton.setAttribute("value", "删除");
deleteButton.onclick = function () { deleteSort(paramCode); };
cell = document.createElement("td");
cell.appendChild(deleteButton);
row.appendChild(cell);
document.getElementById("sortList").appendChild(row);
}
// 删除应用参数函数
function deleteSort(id) {
if (id!=null){
var rowToDelete = document.getElementById(id);
var sortList = document.getElementById("sortList");
sortList.removeChild(rowToDelete);
}
}
二、弹出框页面,新增或者修改参数,并回写相关数据。
<!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>新增应用</title>
<#include "/views/head.html"/>
</head>
<body>
<div class="body-box">
<div class="clear"></div>
<form >
<table width="100%" cellspacing="1" cellpadding="2" border="0" class="pn-ftable">
<tr>
<td>参数名称:</td>
<td class="pn-fcontent"><input type="text" maxlength="20" class="" required="true" id="paramName" name="paramName"/></td>
</tr>
<tr>
<td>参数编码:</td>
<td class="pn-fcontent"><input type="text" maxlength="20" class="" required="true" id="paramCode" name="paramCode" required="true" /></td>
</tr>
<tr>
<td>参数值:</td>
<td class="pn-fcontent"><input type="text" maxlength="20" class="" required="true" id="paramValue" name="paramValue" required="true" /></td>
</tr>
<tr>
<td align="center" colspan="4">
<input type="submit" value="保存" onclick="returnResult();"/>
<input type="button" value="返回" onclick="closeWindow();"/>
</td>
</tr>
</table>
</form>
</div>
</body>
</html>
<script type="text/javascript">
//直接关闭窗口
function closeWindow() {
window.close();
}
//获取值,组装后返回
function returnResult() {
if(!$('form').valid())
return;
var paramName = document.getElementById("paramName");
var paramCode = document.getElementById("paramCode");
var paramValue = document.getElementById("paramValue");
//alert("value is " + paramName.value + "," + paramCode.value + "," + paramValue.value);
var result = paramName.value + "," + paramCode.value + "," + paramValue.value;
window.returnValue = result;
window.close();
}
</script>
G. js动态获取文本框的值
可以使用原生js的document.getElementById("id")方法
document.getElementById("id").value
也可以使用jQuery来获取
$("#id").val()
H. js动态添加html内容
<!DOCTYPEHTML>
<html>
<head>
<title>yugi</title>
<metacharset=UTF-8/>
<styletype="text/css">
</style>
<scripttype="text/javascript">
varadd=function(dom)
{
varp=dom.parentElement,body=document.body,len=body.children.length;
varhtml=p.innerHTML.replace(p.children[p.children.length-1].outerHTML,"")
.replace(/(name["'=]+radio)[^"'s>]+/gim,'$1'+(len+1));
body.innerHTML+="<div>"+html+"</div>";
}
</script>
</head>
<body>
<body>
<div>
<label><inputtype="radio"name="radio1"value="学生"checked="checked"/>A.学生</label>
<label><inputtype="radio"name="radio1"value="教师"/>B.教师</label>
<label><inputtype="radio"name="radio1"value="管理员"/>C.管理员</label>
<label><inputtype="radio"name="radio1"value="管理员"/>D.管理员</label>
<inputtype="button"value="添加"name="add"onclick="add(this);">
</div>
</body>
</html>
I. 只用js如何实现表格内容的动态修改
<body>
<tableid='test'>//定义一个table
<tr>
<td></td><td></td>
</tr>
</table>
<script>
vartb=document.getElementById('test');//获取表格的dom节点
vartd=tb.rows[0].cells[0];//获取0行0列的td单元格
td.innerHTML='222';//动态修改表格的内容为222
</script>
</body>
思路:
1、获取表格的dom节点
2、通过rows和cells定位td单元格
3、通过修改innerHTML
JS实现动态表格的新增,修改,删除操作
一、相关JS函数
function setParamslist() {
var tab = document.getElementById("tab");
//表格行数
var rows = tab.rows.length ;
//表格列数
var cells = tab.rows.item(0).cells.length ;
//alert("行数"+rows+"列数"+cells);
var rowData = "";
for(var i=1;i<rows;i++) {
var cellsData = new Array();
for(var j=0;j<cells-1;j++) {
cellsData.push(tab.rows[i].cells[j].innerText);
}
rowData = rowData + "|" + cellsData;
}
document.getElementById("paramslist").value = rowData;
}
//打开相关新增应用参数界面
function openAppParamsPage() {
var param = new Object();
//这个参数一定要传。
param.win = window;
param.id = 100;
param.name = "test";
param.birthday = new Date();
var result = window.showModalDialog("addParamsItem","dialogWidth:500px;dialogHeight:600px;dialogLeft:200px;dialogTop=200px");
//var temp = document.getElementById("paramslist").value;
//document.getElementById("paramslist").value = temp + result;
addSort(result);
}
// 增加应用参数函数
function addSort(data) {
var name = data;
if(name == ""||name==undefined ) {
return;
}
console.log(data);
var params = data.split(",");
var paramName = params[0];
var paramCode = params[1];
var paramValue = params[2];
var row = document.createElement("tr");
row.setAttribute("id", paramCode);
var cell = document.createElement("td");
cell.appendChild(document.createTextNode(paramName));
row.appendChild(cell);
cell = document.createElement("td");
cell.appendChild(document.createTextNode(paramCode));
row.appendChild(cell);
cell = document.createElement("td");
cell.appendChild(document.createTextNode(paramValue));
row.appendChild(cell);
var deleteButton = document.createElement("input");
deleteButton.setAttribute("type", "button");
deleteButton.setAttribute("value", "删除");
deleteButton.onclick = function () { deleteSort(paramCode); };
cell = document.createElement("td");
cell.appendChild(deleteButton);
row.appendChild(cell);
document.getElementById("sortList").appendChild(row);
}
// 删除应用参数函数
function deleteSort(id) {
if (id!=null){
var rowToDelete = document.getElementById(id);
var sortList = document.getElementById("sortList");
sortList.removeChild(rowToDelete);
}
}
二、弹出框页面,新增或者修改参数,并回写相关数据。
<!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>新增应用</title>
<#include "/views/head.html"/>
</head>
<body>
<div class="body-box">
<div class="clear"></div>
<form >
<table width="100%" cellspacing="1" cellpadding="2" border="0" class="pn-ftable">
<tr>
<td>参数名称:</td>
<td class="pn-fcontent"><input type="text" maxlength="20" class="" required="true" id="paramName" name="paramName"/></td>
</tr>
<tr>
<td>参数编码:</td>
<td class="pn-fcontent"><input type="text" maxlength="20" class="" required="true" id="paramCode" name="paramCode" required="true" /></td>
</tr>
<tr>
<td>参数值:</td>
<td class="pn-fcontent"><input type="text" maxlength="20" class="" required="true" id="paramValue" name="paramValue" required="true" /></td>
</tr>
<tr>
<td align="center" colspan="4">
<input type="submit" value="保存" onclick="returnResult();"/>
<input type="button" value="返回" onclick="closeWindow();"/>
</td>
</tr>
</table>
</form>
</div>
</body>
</html>
<script type="text/javascript">
//直接关闭窗口
function closeWindow() {
window.close();
}
//获取值,组装后返回
function returnResult() {
if(!$('form').valid())
return;
var paramName = document.getElementById("paramName");
var paramCode = document.getElementById("paramCode");
var paramValue = document.getElementById("paramValue");
//alert("value is " + paramName.value + "," + paramCode.value + "," + paramValue.value);
var result = paramName.value + "," + paramCode.value + "," + paramValue.value;
window.returnValue = result;
window.close();
}
</script>