1. 程式人生 > >js滑鼠事件(一)實現banner的輪播效果

js滑鼠事件(一)實現banner的輪播效果

一.要實現的效果

1.點選左右可切換圖片
2.點選小圓點 可切換圖片

二.效果圖

這裡寫圖片描述

三.程式碼

1.css

<style type="text/css">
body,img,span,ul,li{margin: 0;padding: 0;}
#div1{width: 600px;height: 350px;margin: 150px auto;border: 10px solid #eee;position: relative;}
img{width: 600px;height: 350px;}
span{display: inline-block;position: absolute;width
: 50px
;height: 50px;border-radius: 25px;background:rgba(0,0,0,.3); font-size: 30px;line-height: 50px;text-align: center;cursor: pointer;color: white;}
span:hover{background:rgba(255,255,255,.5);color:black;transform:scale(1.3);} span#L{left: 10px;top: 150px;} span#R{right: 10px;top: 150px;} #div1 #ul{position: absolute
;bottom: 10px;left: 250px;width: 125px;height: 20px;}
#div1 #ul li{list-style: none;float: left;height: 20px;width: 20px;border-radius: 10px;background:rgba(255,255,255,.5); margin-right: 5px;cursor: pointer;} #div1 #ul .active{background:rgba(0,0,0,.5);}
</style>

2.html

<body>
    <div id="div1"
>
<img src="" alt=""> <span id="L">&lt;</span> <span id="R">&gt;</span> <ul id="ul"> <li></li> <li></li> <li></li> <li></li> <li></li> </ul> </div> </body>

3.js

<script type="text/javascript">
window.onload=function(){
    var div1=document.getElementById('div1');
    var oImg=div1.getElementsByTagName('img')[0];
    var spanL=document.getElementById('L');
    var spanR=document.getElementById('R');
    var oUl=document.getElementById('ul');
    var oLi=oUl.getElementsByTagName('li');
    var arrImg=['img2/1.jpg','img2/2.jpg','img2/3.jpg','img2/4.jpg','img2/5.jpg'];
    var num=0;
    var oldLi=0;

    function fn(num) {
        oImg.src=arrImg[num];
    }
    fn(0);
    function fnLi(num){
        oLi[oldLi].className='';
       oLi[num].className='active';
       oldLi=num;
    }
    fnLi(0);
    /*點選左右span圖片切換*/
    /*點選左右span時li切換*/
    spanL.onclick=function(){
        if (num<1) {
           num=arrImg.length-1;
           fn(num);
           fnLi(num);
        }else{
           num--;
           fnLi(num);
           fn(num);
        }        
    }
    spanR.onclick=function(){
        if (num==arrImg.length-1) {
           num=0;
           fn(num);
           fnLi(num);
        }else{
           num++;
           fnLi(num);
           fn(num);
        }        
    }
    /*點選li實現圖片切換*/
    for (var i = 0; i < oLi.length; i++) {
        oLi[i].index=i;
        oLi[i].onclick=function(){
            fn(this.index);
            fnLi(this.index);
        }
    }
}
</script>