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
function MTween(obj,attr,end,duration,unit,way,callBack){ if(obj.isAnim) return; //obj开始运动了 自定义属性 obj.isAnim = true; if(!way){ //如果用户没有选择运动方式就默认匀速 way = ‘linear‘; } if(!unit){ //如果用户没有选择运动方式就默认匀速 unit = ‘‘; } var start = parseFloat(getStyle(obj,attr));//起始位置 // var end = 1000;//目标点 // var duration = 1000;//动画执行的总时间 单位是毫秒 var startTime = Date.now(); var s = end - start; //总路程 // var v = s/duration; //计算出来的速度 //每次20ms走一帧 clearInterval(timer); var timer = 0; timer = setInterval(function(){ var endTime = Date.now(); //计算出当前时间 var t = endTime-startTime; if(t>=duration){ t = duration; clearInterval(timer);//到达目标点要清除定时器 } // obj.style[attr] = t*s/duration+start+‘px‘; // console.log(Tween[way](t,start,s,duration)) obj.style[attr] = Tween[way](t,start,s,duration)+unit; //透明度的兼容处理 if(attr==‘opacity‘){ obj.style.filter = ‘Alpha(opacity=‘+Tween[way](t,start,s,duration)*100+‘)‘; } if(t==duration){ obj.isAnim = false; //等到上一个动画完成 然后再调用 if(callBack){ callBack(); } } },20); }
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; } }