js放大镜特效

　　在平时网上商城购物时，我们能够通过放大镜效果来使我们看图片能够更加的清楚，今天我就来给大家分享一下我学习的放大镜特效

　　下图是原图的样子                                                              下图是鼠标放上去的效果

                  

　　接下来我们就看一看放大镜效果是如何实现的

　　1.首先我们还是先把div布局写出来

<div class="bfdj">

    <div id="box">

        <div id="bug1">

            <img src="../img/b2.jpg" alt="" id="bug">

            <div id="ball"></div>

            <div id="mask"></div>

        </div>

        <div id="bug2">

            <img src="../img/b2.jpg" id="pic">

        </div>

    </div>

    <!--小图片五张-->

    <div id="bimg">

        <div id="imgs">

            <img src="../img/b2.jpg" alt="" id="img1">

            <img src="../img/bbbb.jpg" alt="" id="img2">

            <img src="../img/bbbb1.jpg" alt="" id="img3">

            <img src="../img/bbbb2.jpg" alt="" id="img4">

            <img src="../img/bbbb3.jpg" alt="" id="img5">

        </div>

    </div>

</div>

<script src="../js/bf.js"></script>

　　2.其次是css部分

/*放大镜*/
*{
    margin: 0;
    padding: 0;
}
.bfdj{
    width: 100%;
    height: 570px;
    /**/
}
#box{
    width: 375px;
    height: 350px;
    position: relative;
    margin-left: 300px;
    top:100px;
    /*right: ;*/
    /**/
}
#bug1{
    width: 376px;
    height: 350px;
    border: 1px solid gainsboro;
    position: relative;
    display: inline-block;
    /*margin-left: 200px;*/
    /**/
}
/*.box-right{*/
    /*position: absolute;*/
    /*float: right;*/
    /**/
    /*margin-left: 680px;*/
    /*margin-top: -250px;*/
    /*width: 600px;*/
    /*height: 425px;*/
    /*font-size: 16px;*/
    /*font-family: 微软雅黑;*/
    /*border: 1px solid lightgrey;*/
    /*background-image: url("../img/bhh.jpg");*/
/*}*/
#bug1 img{
    width: 100%;
    height: 100%;
    display: block;
}
#ball{
    width: 150px;
    height: 150px;
    position: absolute;
    top:0;
    left: 0;
    background-color: navajowhite;
    opacity: 0.3;
    /*display: none;*/
}
#mask{
    width:100%;
    height: 100%;
    position: absolute;
    top:0;
    left: 0;
    z-index: 5;
    cursor: pointer;
}
#bimg{
    position: relative;
    margin-left: 300px;
    margin-top: 100px;
}
#imgs img{
    width: 70px;
    height: 70px;
    float: left;
    border: 2px solid transparent;
    margin-left: 2px;
    margin-top: 2px;
    position: relative;
    /*margin-left: 400px;*/

}
#imgs img:first-child{
    margin-left: 0;
}
#imgs img:hover{
    border: 2px solid gray;
}

#bug2{
    /**/
    width: 376px;
    height: 350px;
    position: relative;
    top:-355px;
    left: 1px;
    overflow: hidden;
    display: none;
    z-index: 4;
}
#bug2 img{
    width: 400%;
    height: 400%;
    display: block;
    border: none;
    position: absolute;
    z-index: 2;
}

　　3.最后是js部分代码

        //放大镜

        var bug = document.getElementById("bug");

        var img1= document.getElementById("img1")

        var img2= document.getElementById("img2")

        var img3= document.getElementById("img3")

        var img4= document.getElementById("img4")

        var img5= document.getElementById("img5")

        img1.addEventListener("mousemove",function () {

            bug.src="../img/b2.jpg"

        })

        img2.addEventListener("mousemove",function () {

            bug.src="../img/bbbb.jpg"

        })

        img3.addEventListener("mousemove",function () {

            bug.src="../img/bbbb1.jpg"

        })

        img4.addEventListener("mousemove",function () {

            bug.src="../img/bbbb2.jpg"

        })

        img5.addEventListener("mousemove",function () {

            bug.src="../img/bbbb3.jpg"

        })

        var bug1 = document.getElementById("bug1");

        var ball = document.getElementById("ball");

        var bug2= document.getElementById("bug2");

        var rightImg = document.getElementById("pic");

        img1.addEventListener("mousemove",function () {

            rightImg.src="../img/b2.jpg"

        })

        img2.addEventListener("mousemove",function () {

            rightImg.src="../img/bbbb.jpg"

        })

        img3.addEventListener("mousemove",function () {

            rightImg.src="../img/bbbb1.jpg"

        })

        img4.addEventListener("mousemove",function () {

            rightImg.src="../img/bbbb2.jpg"

        })

        img5.addEventListener("mousemove",function () {

            rightImg.src="../img/bbbb3.jpg"

        })

        bug1.onmousemove =function (event) {

                var e = event || window.event; //获取鼠标对象

                ball.style.display="block";

                bug2.style.display="block";

                //鼠标居中

                var x = (e.offsetX || e.layerX) - ball.offsetWidth/2//offsetWidth获取 ball的宽度

                var y = (e.offsetY || e.layerY) - ball.offsetHeight/2

                if(x<=0){

                    x=0;

                }else if(x>box.clientWidth-ball.offsetWidth){

                    x=box.clientWidth-ball.offsetWidth

                }

                if(y<=0){

                    y=0;

                }else if(y>box.clientHeight-ball.offsetHeight){

                    y=box.clientHeight-ball.offsetHeight

                }

                ball.style.left=x+"px";

                ball.style.top=y+"px";

        //四倍大小

                rightImg.style.left= x*-4 +"px"

                rightImg.style.top= y*-4 +"px";

                this.onmouseout =function () {

                    ball.style.display="none";

                    bug2.style.display="none";

                }

            }