JavaScript基于Dom操作实现查找、修改HTML元素的内容及属性的方法

本文实例讲述了JavaScript基于Dom操作实现查找、修改HTML元素的内容及属性的方法。分享给大家供大家参考,具体如下:

当网页被加载时,浏览器会创建页面的文档对象模型(Document Object Model)。HTML DOM 模型被构造为对象的树。

通过可编程的对象模型,JavaScript 获得了足够的能力来创建动态的 HTML。例如:改变HTML元素,改变HTML属性,改变CSS样式,事件响应。

效果图:

代码:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html>

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

<meta http-equiv="Content-Language" content="zh-cn" />

<title>Javascript HTML DOM</title>

<head>

<style type="text/css">

body {background-color:#eeeeee}

</style>

</head>

<body>

<h3>(一)通过 id 查找 HTML 元素</h3>

<p id = "hw">Hello world!</p>

<script>

x = document.getElementById("hw");

document.write('<p>id="hw"的段落的文本是:'+x.innerHTML+'</p>');

</script>

<button onclick = "setCurrentTime()">将id="hw"的文字改为当前时间</button>

<script>

function setCurrentTime(){

x = document.getElementById("hw");

x.innerHTML = Date()

}

</script>

<h3>(二)通过 标签名 查找 HTML 元素</h3>

<div id = "mainDiv">

<p>This is a paragragph.</p>

<p>This is another paragragph.</p>

<p>Yes you're right! This is also paragragph.</p>

</div>

<script>

xx = document.getElementById("mainDiv");

tagContents = xx.getElementsByTagName("p");

document.write("<p>使用Javascript查找id为mainDiv下的p标签的内容</p>");

for(i=0;;i++){

var tag = tagContents[i]

if(tag!=null){

document.write("<p>"+tag.innerHTML+"</p>")

}else{

document.write("<p>共有"+i+"条内容</p>")

break;

}

}

</script>

<h3>(三)修改 HTML 的属性</h3>

<img id = "bol" src = "images/eg_bulboff.gif" width="70px" height="120px"/>

<p><button onclick = "changeSrc()">改变图片资源</button></p>

<script>

function changeSrc(){

x = document.getElementById("bol");

if (x.src.match("eg_bulboff.gif")){

x.src = "images/eg_bulbon.gif"

}else{

x.src = "images/eg_bulboff.gif"

}

}

</script>

<h3>(四)修改 CSS 样式</h3>

<p>

<span id = "para_1">This is a test paragraph.</span>

<button onclick="changeTextColor()">改变文字颜色</button>

</p>

<p>

<span id = "para_2">This is another paragraph.

<button onclick="changeTextFont()">改变字体</button>

</p>

<p>

<span id = "para_3">This is HELLO WORLD.</span>

<button onclick="changeTextSize()">改变字号</button>

</p>

<p>

<button onclick="changeVisibility()">显示/隐藏</button>

<span id = "para_4">示例文字</span>

</p>

<script>

function changeTextColor(){

ele_1 = document.getElementById("para_1");

ele_1.style.color = "red";

}

function changeTextFont(){

ele_2 = document.getElementById("para_2");

ele_2.style.fontFamily = "Arial";

}

function changeTextSize(){

ele_3 = document.getElementById("para_3");

ele_3.style.fontSize = "larger";

}

document.getElementById("para_4").style.visibility = "visible"

function changeVisibility(){

ele_4 = document.getElementById("para_4");

if(ele_4.style.visibility.match("visible")){

ele_4.style.visibility = "hidden"

}else{

ele_4.style.visibility = "visible"

}

}

</script>

</body>

</html>

更多关于JavaScript相关内容感兴趣的读者可查看本站专题:《JavaScript事件相关操作与技巧大全》、《JavaScript操作DOM技巧总结》、《JavaScript错误与调试技巧总结》、《JavaScript数据结构与算法技巧总结》、《JavaScript遍历算法与技巧总结》及《JavaScript数学运算用法总结》

希望本文所述对大家JavaScript程序设计有所帮助。

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