本文实例为大家分享了js实现导航栏上下动画的具体代码，供大家参考，具体内容如下
obj.currentStyle[name] 与 getComputedStyle(obj,false)[name] ，一个是支持IE 一个支持FE
完美运动js插件，能根据传进来的值，进行匹配，从而得到了理想的运动效果，也就是运行逻辑。
实现上下动画动画效果就是控制元素height的值，通过不断的修改该值，就能呈现所谓的动画效果，这里就需要用到定时器
定时器有两种
重复不断的定时器 setInterval(fn,time);
延时只在设定时间后只出现一次的定时器 setTimeout(fn,time)
在遍历传进的每一个值，需要使用一个boolean来控制是否完成解析，解析成功则返回true，结束定时器，返回false,知道返回true位置
function getStyle(obj, attr)
{
?? ?if(obj.currentStyle)
?? ?{
?? ??? ?return obj.currentStyle[attr];
?? ?}
?? ?else
?? ?{
?? ??? ?return getComputedStyle(obj, false)[attr];
?? ?}
}
function startMove(obj,json,fnEnd){
?? ?if(obj.timer){
?? ??? ?clearInterval(obj.timer);
?? ?};
?? ?obj.timer=setInterval(function(){
?? ??? ?var bStop = true; //假设全部找到
?? ??? ?for(var attr in json){
?? ??? ??? ?var icurr = 0;
?? ??? ??? ?if(attr=='opacity'){//匹配key
?? ??? ??? ??? ?icurr=Math.round(parseFloat(getStyle(obj,attr))*100); //获取元素的属性值
?? ??? ??? ?}else{
?? ??? ??? ??? ?icurr=parseInt(getStyle(obj,attr));
?? ??? ??? ?};
?? ??? ??? ?var sPeed = (json[attr]-icurr)/8;
?? ??? ??? ?sPeed=sPeed>0?Math.ceil(sPeed):Math.floor(sPeed);
?? ??? ??? ?if(attr=='opacity'){
?? ??? ??? ??? ?obj.style.filter="alpha(opacity:"+(icurr+sPeed)+")";
?? ??? ??? ??? ?obj.style.opacity=(icurr+sPeed)/100;
?? ??? ??? ?}else{
?? ??? ??? ??? ?obj.style[attr]=icurr+sPeed+'px';
?? ??? ??? ?}
?? ??? ??? ?if(icurr!=json[attr]){
?? ??? ??? ??? ?bStop=false;
?? ??? ??? ?}
?? ??? ?}
?? ??? ?if(bStop){
?? ??? ??? ?clearInterval(obj.timer);
?? ??? ??? ?if(fnEnd){
?? ??? ??? ??? ?fnEnd();
?? ??? ??? ?}
?? ??? ?}
?? ?},30);
}
// alert('dffe');
html布局
<!DOCTYPE html> <html lang="zh"> <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"> <link rel="stylesheet" type="text/css" href="css/common.css" /> <script src="js/move.js"></script> <script src="js/common.js"></script> <title></title> </head> <body> <div id="box"> <div><a href="javascript:;" class="a01"></a><em>关于</em><span></span></div> <div><a href="javascript:;" class="a02"></a><em>招聘</em><span></span></div> <div><a href="javascript:;" class="a04"></a><em>产品</em><span></span></div> <div><a href="javascript:;" class="a03"></a><em>公司</em><span></span></div> </div> </body> </html>
css文件
*{
?? ?margin: 0;
?? ?padding: 0;
}
a{
?? ?text-decoration: none;
}
body{
?? ?background-color: #c1c1c1;
}
#box{
?? ?width: 880px;
?? ?margin: 100px auto;
?? ?overflow: hidden;
}
#box div{
?? ?width: 200px;
?? ?height: 100px;
?? ?float: left;
?? ?overflow: hidden;
?? ?position: relative;
}
#box div a{
?? ?position: absolute;
?? ?left: 0;
?? ?top: 0;
?? ?width: 200px;
?? ?height: 100px;
?? ?display: block;
?? ?/* background-color: red; */
background: url(images/1.jpg) no-repeat;
}
#box div span{
?? ?display: block;
?? ?width: 200px;
?? ?height: 100px;
?? ?position: absolute;
?? ?background: url(images/window.png) left top repeat-x;
}
#box div em{
?? ?display: block;
?? ?width: 100%;
?? ?height: 100%;
?? ?background-color: #999;
?? ?position: absolute;
?? ?text-align: center;
?? ?line-height: 100px;
?? ?font-family: Verdana;
?? ?font-style: normal;
?? ?font-size: 30px;
?? ?color: white;
?? ?text-shadow: 2px 1px 4px black;
?? ?top: 0;
}
#box div a.a01{
?? ??? ?/* background: url(images/1.jpg) 0 5px no-repeat; */
?? ?background-position: 0 5px;
}
#box div a.a02{
?? ??? ?/* background: url(images/1.jpg) 0 5px no-repeat; */
?? ?background-position: -200px 5px;
}
#box div a.a03{
?? ??? ?/* background: url(images/1.jpg) 0 5px no-repeat; */
?? ?background-position: -400px 5px;
}
#box div a.a04{
?? ??? ?/* background: url(images/1.jpg) 0 5px no-repeat; */
?? ?background-position: -600px 5px;
}
window.οnlοad=fn
window.onload=function(){
?? ?var oDiv = document.getElementById('box');
?? ?var aDiv = oDiv.getElementsByTagName('div');
?? ?var aEm = oDiv.getElementsByTagName('em');
?? ??? ?var aEm = oDiv.getElementsByTagName('em');
?? ?for(var i=0;i<aDiv.length;i++)
?? ??? ?{
?? ??? ??? ?aDiv[i].index = i;
?? ??? ??? ?aDiv[i].onmouseover = function()
?? ??? ??? ?{
?? ??? ??? ??? ?startMove(aEm[this.index],{top:-aEm[this.index].offsetHeight})
?? ??? ??? ?}
?? ??? ??? ?aDiv[i].onmouseout = function()
?? ??? ??? ?{
?? ??? ??? ??? ?startMove(aEm[this.index],{top:0})
?? ??? ??? ?}
?? ??? ?}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
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