原生js实现简单的焦点图效果

蔚落 2023-06-10 14:24 54阅读 0赞

用到一些封装好的运动函数，主要是定时器

效果为图片和图片的描述定时自动更换

<!DOCTYPE html>
    <html>
    
        <head>
            <meta charset="UTF-8">
            <title></title>
            <style type="text/css"> ul, li, p, h3 { padding: 0; margin: 0; list-style: none; } img { border: none; vertical-align: top; } #bg_box { width: 1000px; height: 590px; margin: 50px auto; position: relative; background: url(img/bg1.jpg) no-repeat;
     } .pic { width: 440px; height: 274px; position: absolute; top: 50px; left: 220px; overflow: hidden; } .li_box { width: 1760px; height: 274px; position: absolute; left: 0; } .tags { width: 440px; height: 80px; position: absolute; bottom: -80px; background-image: linear-gradient(0deg, rgba(0, 0, 0, 0.4) 0%, rgba(255, 255, 255, 0) 100%); color: white; padding-left: 20px; padding-top: 15px; box-sizing: border-box; } .tags:nth-of-type(1) { /*bottom: 0;*/ } .img { float: left; width: 440px; height: 274px; } h3 { font: bold 20px/30px "微软雅黑";
     } p { font: 16px/30px "微软雅黑";
     } </style>
            <script src="tween.js"></script>
            <script src="commom.js"></script>
            <script type="text/javascript"> window.onload = function() { //获取元素
                    var liBbox = $('ul')[0]; var li = $('li'); var tags = $('.tags') var num = 0; //设置初始位置
     Change() function Change() { var M = tags[num]; MTween(M, 'bottom', 0, 500, 'px', 'linear', function() { //先让描述内容出现
                            num  
                            if(num > li.length - 1) { //边界设置。
                                return; } setTimeout(function() { MTween(M, 'bottom', -80, 500, 'px', 'linear', function() { //让描述内容不显示
                                    MTween(liBbox, 'left', -num * 440, 800, 'px', 'linear', function() { Change(); }); //切换图片
     }); }, 1000) }); } } </script>
        </head>
    
        <body>
            <section id="bg_box">
                <div class="pic">
                    <ul class="li_box">
                        <li>
                            <img class="img" src="img/a5.gif">
                        </li>
                        <li>
                            <img class="img" src="img/a6.gif">
                        </li>
                        <li>
                            <img class="img" src="img/a7.gif">
                        </li>
                        <li>
                            <img class="img" src="img/a8.gif">
                        </li>
                    </ul>
                    <div class="tags">
                        <h3 class="title">下雨了~~~</h3>
                        <p class="tag">这是一个适合在家睡觉的日子!!</p>
                    </div>
                    <div class="tags">
                        <h3 class="title">包饺子~~~</h3>
                        <p class="tag">一只会居家过日子的小狐狸！！</p>
                    </div>
                    <div class="tags">
                        <h3 class="title">生气了~~~</h3>
                        <p class="tag">吃掉好吃的就不生气了！！</p>
                    </div>
                    <div class="tags">
                        <h3 class="title">出发了~~~</h3>
                        <p class="tag">来一段说走就走的旅行!!</p>
                    </div>
                </div>
            </section>
        </body>
    
    </html>

commom.js

tween.js

/* * t : time 已过时间 当前时间-初始时间 * b : begin 起始值 * c : count 总的运动值 总路程 * d : duration 持续时间 总时间 * * s = vt; => c = t*c/d 这里只计算总共要运动的路程 ，不包括起始位置 * * attrVal = t*c/d b; * * 曲线方程 * * http://www.cnblogs.com/bluedream2009/archive/2010/06/19/1760909.html * */
    
    //Tween.linear();
    
    var Tween = { linear: function (t, b, c, d){  //匀速
            return c*t/d   b;
     }, easeIn: function(t, b, c, d){  //加速曲线
            return c*(t/=d)*t   b;
     }, easeOut: function(t, b, c, d){  //减速曲线
            return -c *(t/=d)*(t-2)   b;
     }, easeBoth: function(t, b, c, d){  //加速减速曲线
            if ((t/=d/2) < 1) { return c/2*t*t   b;
     } return -c/2 * ((--t)*(t-2) - 1)   b;
     }, easeInStrong: function(t, b, c, d){  //加加速曲线
            return c*(t/=d)*t*t*t   b;
     }, easeOutStrong: function(t, b, c, d){  //减减速曲线
            return -c * ((t=t/d-1)*t*t*t - 1)   b;
     }, easeBothStrong: function(t, b, c, d){  //加加速减减速曲线
            if ((t/=d/2) < 1) { return c/2*t*t*t*t   b;
     } return -c/2 * ((t-=2)*t*t*t - 2)   b;
     }, elasticIn: function(t, b, c, d, a, p){  //正弦衰减曲线（弹动渐入）
            if (t === 0) { return b; } if ( (t /= d) == 1 ) {
                return b c; } if (!p) { p=d*0.3; } if (!a || a < Math.abs(c)) { a = c; var s = p/4;
            } else { var s = p/(2*Math.PI) * Math.asin (c/a); } return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p ))   b;
     }, elasticOut: function(t, b, c, d, a, p){    //*正弦增强曲线（弹动渐出）
            if (t === 0) { return b; } if ( (t /= d) == 1 ) {
                return b c; } if (!p) { p=d*0.3; } if (!a || a < Math.abs(c)) { a = c; var s = p / 4; } else { var s = p/(2*Math.PI) * Math.asin (c/a); } return a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p )   c   b;
     }, elasticBoth: function(t, b, c, d, a, p){ if (t === 0) { return b; } if ( (t /= d/2) == 2 ) { return b c; } if (!p) { p = d*(0.3*1.5); } if ( !a || a < Math.abs(c) ) { a = c; var s = p/4;
     } else { var s = p/(2*Math.PI) * Math.asin (c/a); } if (t < 1) { return - 0.5*(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p ))   b;
     } return a*Math.pow(2,-10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )*0.5   c   b;
     }, backIn: function(t, b, c, d, s){     //回退加速（回退渐入）
            if (typeof s == 'undefined') { s = 1.70158; } return c*(t/=d)*t*((s 1)*t - s)   b;
     }, backOut: function(t, b, c, d, s){ if (typeof s == 'undefined') { s = 3.70158;  //回缩的距离
     } return c*((t=t/d-1)*t*((s 1)*t   s)   1)   b;
     }, backBoth: function(t, b, c, d, s){ if (typeof s == 'undefined') { s = 1.70158; } if ((t /= d/2 ) < 1) { return c/2*(t*t*(((s*=(1.525)) 1)*t - s))   b;
     } return c/2*((t-=2)*t*(((s*=(1.525)) 1)*t   s)   2)   b;
     }, bounceIn: function(t, b, c, d){    //弹球减振（弹球渐出）
            return c - Tween['bounceOut'](d-t, 0, c, d)  b; }, bounceOut: function(t, b, c, d){
        //*
            if ((t/=d) < (1/2.75)) { return c*(7.5625*t*t)  b; } else if (t < (2/2.75)) {
                return c*(7.5625*(t-=(1.5/2.75))*t   0.75)   b;
            } else if (t < (2.5/2.75)) {
                return c*(7.5625*(t-=(2.25/2.75))*t   0.9375)   b;
     } return c*(7.5625*(t-=(2.625/2.75))*t   0.984375)   b;
     }, bounceBoth: function(t, b, c, d){ if (t < d/2) {
                return Tween['bounceIn'](t*2, 0, c, d) * 0.5  b; } return Tween['bounceOut'](t*2-d, 0, c, d) * 0.5   c*0.5  b; } }

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