javascript-展开与收起

<!DOCTYPE html>
<html>
<head>
<title>收缩</title>
<meta charset="utf-8"/>
<style type="text/css">
body{ margin: 0 auto;padding: 0px;}
#layout{background: #e8e8e8; 600px;height: auto;margin: 0 auto;padding: 5px;font-size: 9pt;}
.slide{margin: 0;padding: 0; 600px;border-top: solid 4px gray;margin: 0 auto;}
.slide a{background: gray;text-decoration: none;text-align: center; 120px;height: 30px;padding: 10px 0 0 0;display: block;color: #FFF;margin: 0 auto;}
</style>
</head>
<body>
    <div id="layout">
        <p>手机 - 商品筛选</p>
        <p> 网络:移动4G 联通3G 电信3G</p>
        <div id="hideWrap" style="display: none">
            <p>价格:5000元以上 4000-4999 3000元以下</p>
            <p>特点:0元购机 防水 长待机</p>
        </div>
    </div>
    <p class="slide" id="slide">
        <a href="#" id="btn" class="open">展开</a>
    </p>
</body>
<script type="text/javascript">
function getClassName (id, cls) {
    var eleId = id ? document.getElementById(id) : document;
    var elements = eleId.getElementsByTagName('*');
    var classNames = [];
    for(var i = 0, l = elements.length; i < l; i++){
        if(elements[i].className == cls){
            classNames.push(elements[i]);
        }
    }
    return classNames;
}

function show(ele, bt){
   ele.style.display = 'block';
   bt.innerHTML = '收起-';
   bt.className = 'colse';
   bt.id = 'btnCos';
}
function hide(ele, bt){
    ele.style.display = 'none';
    bt.innerHTML = '展开+';
    bt.className = 'open';
}
window.onload = function(){
    var hideWrap = document.getElementById('hideWrap');
    var btn = document.getElementById('btn');
    var btnCos = document.getElementById('btnCos');
    btn.onclick = function(){
       
        //搞了半天搞明白了 哎
        var ele = getClassName('slide', 'open')[0] || getClassName('slide', 'colse')[0];
        if(ele){
            var className = ele.className;
        }
        if(className == 'open'){
           show(hideWrap, btn);
        }else if(className == 'colse'){
            hide(hideWrap, btn);
        }else{
            return;
        }
    }
}
</script>
</html>
原文地址:https://www.cnblogs.com/sunhw360/p/4139806.html