JavaScript原生代码实现导航栏小效果

今天药忘吃喽~ 2022-06-01 06:49 236阅读 0赞

<!doctype html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport"
              content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
        <meta http-equiv="X-UA-Compatible" content="ie=edge">
        <title>Document</title>
        <style>
            *{
                padding: 0;
                margin: 0;
            }
    
            body{
                background-color: rgba(0,0,0,0.7);
            }
            ul{
                position: relative;
            }
            li{
                list-style: none;
                float: left;
                width: 83px;
                height: 42px;
                text-align: center;
                cursor: pointer;
                font: 400 16px/42px microsoft yahei;
            }
            .box{
                width: 664px;
                height: 42px;
                margin: 200px auto;
                background: #fff ;
                position: relative;
                border-radius: 7px;
            }
            span{
                position: absolute;
                width: 83px;
                height: 42px;
                left: 0;
                top: 0;
                border-radius: 7px;
                background-color:pink;
            }
        </style>
    
    
        <script>
            window.onload = function () {
    
                // 获取相关元素
                var btn  = document.getElementsByTagName("span")[0];
                var ul = document.getElementsByTagName("ul")[0];
                var liarr = ul.children;
                var  liwidth = liarr[0].offsetWidth;
    
                //获取相关元素，绑定事件，书写事件驱动程序
                var raw = 0;
                for (var i = 0; i<liarr.length ;i++){
                    // 给元素绑定index属性；
                    liarr[i].index = i;
    
                    liarr[i].onmouseover = function () {
                        animate(btn,this.index*liwidth);
    
                    }
                    liarr[i].onmouseout = function () {
                        animate(btn,raw*liwidth);
                    }
                    liarr[i].onclick = function () {
                        raw = this.index;
                    }
                }
    
    
    
    
                //缓动动画封装
                function animate(ele,target) {
                    clearInterval(ele.timer);
                    ele.timer = setInterval(function () {
                        var step = (target-ele.offsetLeft)/10;
                        step = step>0?Math.ceil(step):Math.floor(step);
                        ele.style.left = ele.offsetLeft + step + "px";
                        console.log(1);
                        if(Math.abs(target-ele.offsetLeft)<Math.abs(step)){
                            ele.style.left = target + "px";
                            clearInterval(ele.timer);
                        }
                    },18);
                }
    
            }
        </script>
    </head>
    
    <body>
    <div class="box">
        <span></span>
        <ul>
            <li>首页新闻</li>
            <li>首页新闻</li>
            <li>首页新闻</li>
            <li>首页新闻</li>
            <li>首页新闻</li>
            <li>首页新闻</li>
            <li>首页新闻</li>
            <li>首页新闻</li>
        </ul>
    </div>
    </body>
    </html>