JS 放大鏡(淘寶商品放大鏡)的實現
阿新 • • 發佈:2019-02-11
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
*{
padding: 0;
margin: 0;
}
.box{
margin: 100px;
border : 1px solid #fff;
position: relative;
}
.small{
position: relative;
width: 350px;
height: 350px;
}
.mask{
width: 175px;
height: 175px;
background : rgba(255, 255, 0, 0.4);
position: absolute;
left: 0;
top: 0;
display: none;
cursor: move;
}
.big{
width: 400px;
height: 400px;
border: 1px solid #fff;
position : absolute;
top: 0;
left: 360px;
overflow: hidden;
display: none;
}
</style>
<script type="text/javascript" src="js/animate.js"></script>
<script type="text/javascript">
window.onload = function(){
var box = document.getElementsByClassName("box")[0];
var small = box.children[0];
var big = box.children[1];
var bigImg = big.children[0];
var mask = small.children[1];
//big和mask在滑鼠移入small時顯示,移出時隱藏
small.onmouseenter = function(){
big.style.display = "block";
mask.style.display = "block";
};
small.onmouseleave = function(){
big.style.display = "none";
mask.style.display = "none";
};
small.onmousemove = function(event){
event = event || window.event;
//mask跟隨滑鼠移動,且不會超出small範圍
//x作為mask的left值,y作mask的top值。
var pagex = event.pageX || scroll().left + event.clientX;
var pagey = event.pageY || scroll().top + event.clientY;
//減去mask寬高的一半,讓滑鼠在mask的中間
var x = pagex - box.offsetLeft - mask.offsetWidth/2;
var y = pagey - box.offsetTop - mask.offsetHeight/2;
//不讓mask超出small
if(x < 0){
x=0;
}
if(x > small.offsetWidth - mask.offsetWidth){
x = small.offsetWidth - mask.offsetWidth;
}
if(y < 0){
y=0;
}
if(y > small.offsetHeight - mask.offsetHeight){
y = small.offsetHeight - mask.offsetHeight;
}
mask.style.left = x + "px";
mask.style.top = y + "px";
//bigImg隨著mask的移動移動
//比例 = 大圖移動的距離/mask移動的距離 = 大圖/小圖
var scale = bigImg.offsetWidth / small.offsetWidth;
bigImg.style.marginLeft = -scale * x +"px";
bigImg.style.marginTop = -scale * y +"px";
}
};
</script>
</head>
<body>
<div class="box">
<div class="small">
<img src="img/IMG_2840(1.jpg"/>
<div class="mask"></div>
</div>
<div class="big">
<img src="img/IMG_2840.JPG"/>
</div>
</div>
</body>
</html>
效果: