js 评论列表推送动画系列一 

// qq音乐app观看mv的时候评论推送动画 看到了实现一下
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>js 评论列表推送动画系列一</title>
    <style>
        .box  {
            width: 400px;
            height: 400px;
            border: 1px solid #ccc;
            margin: 0 auto;
            position: relative;
            overflow: hidden;
        }
        ul {
            list-style: none;
            margin: 0;
            padding: 0;
            position: absolute;
            bottom: 20px;
            left: 20px;
        }
        li {
            border-radius: 20px;
            line-height: 40px;
            border: 1px solid #ccc;
            position: absolute;
            transition: all 1s;
            padding: 0 20px;
            margin: 0;
            opacity: 0;
            bottom: -40px;
            opacity: 0;
            color: #666;
            max-width: 0;
            height: 0px;
            white-space: nowrap;
        }
        .active {
            max-width: 300px;
            height: 40px;
            opacity: 1;
            animation: fade 2s linear 3s forwards;
        }
        @keyframes fade{
            from {
                opacity: 1;
            }
            to {
                opacity: 0;
            }
        }
    </style>
</head>
<body>
    <div class="box">
        <ul class="list"></ul>  
    </div>
    <script>
        var parent = document.getElementsByClassName('list')[0]
        var num = 0
        var t = setInterval(() => {
            num++
            var para = document.createElement("li");//获取父节点
            para.innerHTML = '醉赤壁好听 +' + num
            parent.insertBefore(para, parent.children[0]);//添加至父节点内
            var list = document.getElementsByTagName('li')
            if (list.length > 6 ) {
                parent.removeChild(parent.lastChild)
            }
            for (let i = 0; i < list.length; i++) {
                const element = list[i];
                element.style.bottom = (52 * (i - 1)) + 'px'
                if (i === 1) {
                    element.classList.add('active')
                }
            }
            
        }, 1000)
        
    </script>
</body>
</html>

 

posted @ 2019-06-26 22:53  怎么说好呢  阅读(243)  评论(0)    收藏  举报