实现jquery放大镜的两种方法
作者：web_emmet
本篇文章给大家详细分析了用jquery实现放大镜效果的方法，以及代码分享，有兴趣的学习下。
jquery写的两种放大镜效果，没有使用到插件。调理和思路清晰。不是使用面向对象方式写的，初学者较容易看懂。废话不多说，看代码。图片这里就不上传了，大家自己找下。最好是找到比例的，这样效果比较好。
<body>
<div id="father">
<div id="container">
<img src="img/400_1.jpg" style="display: block;">
<img src="img/400_2.jpg" >
<div class="shade"></div>
</div>
<div class="small first"><img src="img/50_1.jpg"></div>
<div class="small second"><img src="img/50_2.jpg"></div>
</div>
<div class="big">
<img src="img/800_1.jpg" style="display: block;">
<img src="img/800_2.jpg">
</div>
</body>
css代码
*{padding: 0; margin: 0;}
#father .small{width: 50px; height: 50px; border: 2px solid #ccc; bottom: 0; position: absolute;}
#father .second{left: 70px;}
.third{left: 140px;}
#father{position: relative; top: 100px; left: 50px; height: 460px;}
#container{position: absolute; width: 400px; height: 400px;}
#container img{position: absolute; display: none;}
.shade{width: 200px; height: 200px; position: absolute; background: #000; opacity: 0.4; top: 0;
left: 0; display: none;}
.big{width: 400px; height: 400px; position: absolute; top: 100px; overflow: hidden; left: 500px; display: none;}
.big img{width: 800px; height: 800px; position: absolute; display: none;}
js代码
<script type="text/javascript" src='js/jquery-1.12.4.min.js'></script>
<script type="text/javascript">
$(function () {
changePic('.first',0);
changePic('.second',1);
var shadeWidth = $('.shade').width(),//阴影的宽度
shadeHeight = $('.shade').height(),//阴影的高度
middleWidth = $('#container').width(),//容器的宽度
middleHeight = $('#container').height(),//容器的高度
bigWidth = $('.big').width(),//放大图片盒子的宽度
bigHeight = $('.big').height(),//放大图片盒子的高度
rateX = bigWidth / shadeWidth,//放大区和遮罩层的宽度比例
rateY = bigHeight / shadeHeight;//放大区和遮罩层的高度比例
//当鼠标移入与移出时阴影与放大去显现/消失
$('#container').hover(function() {
$('.shade').show();
$('.big').show();
}, function() {
$('.shade').hide();
$('.big').hide();
}).mousemove(function(e) {//当鼠标移动时，阴影和放大区图片进行移动
//记录下光标距离页面的距离
var x = e.pageX,
y = e.pageY;
//设置遮罩层的位置
$('.shade').offset({
top: y-shadeHeight/2,
left: x-shadeWidth/2
});
//获取遮罩层相对父元素的位置
var cur = $('.shade').position(),
_top = cur.top,
_left = cur.left,
hdiffer = middleHeight - shadeHeight,
wdiffer = middleWidth - shadeWidth;
if (_top < 0) _top = 0;
else if (_top > hdiffer) _top = hdiffer;
if (_left < 0) _left = 0;
else if (_left > wdiffer) _left =wdiffer;
//判断完成后设置遮罩层的范围
$('.shade').css({
top: _top,
left: _left
});
//设置放大区图片移动
$('.big img').css({
top: - rateY*_top,
left: - rateX*_left
});
});;
//封装的改变图片显示的函数
function changePic (element,index) {
$(element).click(function() {
$('#container img').eq(index).css('display', 'block').siblings().css('display', 'none');
$('.big img').eq(index).css('display', 'block').siblings().css('display', 'none');
});
}
});
以上是常用的，下面这个是在原图基础上放大的
htm
<body>
<div id="father">
<div id="container">
<img src="img/400_1.jpg" style="display: block;">
<img src="img/400_2.jpg" >
<img src="img/400_3.jpg" >
<div class="shade">
<img src="img/800_1.jpg" style="display: block;">
<img src="img/800_2.jpg">
<img src="img/800_3.jpg">
</div>
</div>
<div class="small first"><img src="img/50_1.jpg"></div>
<div class="small second"><img src="img/50_2.jpg"></div>
<div class="small third"><img src="img/50_3.jpg"></div>
</div>
</body>
css代码
*{padding: 0; margin: 0;}
#father .small{width: 50px; height: 50px; border: 2px solid #ccc; bottom: 0; position: absolute;}
#father .second{left: 70px;}
.third{left: 140px;}
#father{position: relative; top: 100px; left: 50px; height: 460px;}
#container{position: absolute; width: 400px; height: 400px;}
#container img{position: absolute; display: none;}
.shade{width: 200px; height: 200px; position: absolute; top: 0;left: 0; display: none; border-radius: 50%; overflow: hidden; background: #000;}
.shade img{display: none; width: 800px; height: 800px; position: absolute;}
js代码
<span style="white-space:pre"> </span><script type="text/javascript" src='js/jquery-1.12.4.min.js'></script>
<script type="text/javascript">
$(function () {
changePic('.first',0);
changePic('.second',1);
changePic('.third',2);
var shadeWidth = $('.shade').width(),//阴影的宽度
shadeHeight = $('.shade').height(),//阴影的高度
middleWidth = $('#container').width(),//容器的宽度
middleHeight = $('#container').height(),//容器的高度
bigImgWidth = $('.shade img').width(),//放大图片盒子的宽度
bigImgHeight = $('.shade img').height(),//放大图片盒子的高度
rateX = bigImgWidth / middleWidth,//放大区和遮罩层的宽度比例2
rateY = bigImgHeight / middleHeight;//放大区和遮罩层的高度比例2
//当鼠标移入与移出时阴影与放大去显现/消失
$('#container').hover(function() {
$('.shade').show();
$('.big').show();
}, function() {
$('.shade').hide();
$('.big').hide();
}).mousemove(function(e) {//当鼠标移动时，阴影和放大区图片进行移动
//记录下光标距离页面的距离
var x = e.pageX,
y = e.pageY;
//设置遮罩层的位置
$('.shade').offset({
top: y-shadeHeight/2,
left: x-shadeWidth/2
});
//获取遮罩层相对父元素的位置
var cur = $('.shade').position(),
_top = cur.top,
_left = cur.left,
hdiffer = middleHeight - shadeHeight,
wdiffer = middleWidth - shadeWidth;
if (_top < 0) _top = 0;
else if (_top > hdiffer) _top = hdiffer;
if (_left < 0) _left = 0;
else if (_left > wdiffer) _left =wdiffer;
//判断完成后设置遮罩层的范围
$('.shade').css({
top: _top,
left: _left
});
//设置放大区图片移动
$('.shade img').css({
top: - _top*rateY*3/2,
left: - _left*rateX*3/2
});
});;
//封装的改变图片显示的函数
function changePic (element,index) {
$(element).click(function() {
$('#container img').eq(index).css('display', 'block').siblings().css('display', 'none');
$('.shade img').eq(index).css('display', 'block').siblings().css('display', 'none');
});
}
});
<span style="white-space:pre"> </span></script>