(三) DOM和事件

1. childNodes和nodeType必须配合使用

    childNodes在IE中不包括文本,但在火狐中包含文本  

<!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>无标题文档</title>
<script type="text/javascript">
window.onload = function(){
	// childNodes 和 nodeType要配合使用
	var oUl = document.getElementById("ul1");
	var i = 0; 
	for(i = 0; i < oUl.childNodes.length; i++){
		if(oUl.childNodes[i].nodeType == 1){ // 等于1表示元素结点
			oUl.childNodes[i].style.background = 'red';
		}
	}
	alert(oUl.children.length);  // children是childNodes的兼容版
}
</script>
</head>

<body>
	<ul id="ul1">
    	<li></li>
        <li></li>
        <li></li>
    </ul>
</body>
</html>

2. 点和[]

<script type="text/javascript">
window.onload = function(){
	var oTxt = document.getElementById('txt1');
	oTxt.value = '123';  // 1
	oTxt['value'] = 'abc'; // 2    第一种方法和第二种方法一样
    oTxt.setAttribute('value', 'cde'); // 3 同 1, 2
}
</script>

3. 通过className选择元素

<!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>无标题文档</title>
<script type="text/javascript">
	function getNodesByClass(oParent, sClass){
		var aEle = oParent.getElementsByTagName('*');
		var aResult = [];
		var i = 0;
		for(i = 0; i < aEle.length; i++){
			if(aEle[i].className == sClass){
				aResult.push(aEle[i]);
			}
		}
		return aResult;
	}
	window.onload = function(){
		var oUl = document.getElementById("ul1");
		var aBox = getNodesByClass(oUl, 'box');
		var i = 0;
		for(i = 0; i < aBox.length; i++){
			aBox[i].style.background = 'red';
		}
	}
</script>
</head>

<body>
	<ul id="ul1">
    	<li></li>
        <li class="box"></li>
        <li></li>
        <li class="box"></li>
    </ul>
</body>
</html>

dom

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