<!DOCTYPE HTML>
<html lang="en-US">
<head>
<meta charset="UTF-8">
<title>原生Js结合html5做出放大镜的效果</title>
<style>
img{
margin:100px 500px;
}
div{
width:200px;
height:200px;
display:none;
border:1px solid #ccc;
border-radius:100px;
z-index:1000;
pointer-events:none;
}
</style>
</head>
<body>
<img src="http://d.hiphotos.baidu.com/image/w%3D2048/sign=529c3afe39c79f3d8fe1e3308e99cc11/7a899e510fb30f24d9069302ca95d143ad4b0316.jpg" onload="core(this)"></img>
<div id="showImg"></div>
<script>
//图片加载完成之后，触发这个方法
function core(obj){
//加载完成之后，就将图片大小设置完成
obj.width = "400";
var new_div = document.getElementById("showImg");
//现在图片的大小
var width_changed = obj.width;
var height_changed = obj.height;
//得到原图的真正的宽高
var img = new Image();
img.src = obj.src;
var width_start = "";
var height_start = "";
//需要在加载完成之后再获取到原图的宽高
img.onload = function(){
width_start = img.width;
height_start = img.height;
//在最开始就设置背景图片
new_div.style.backgroundImage = "url("+this.src+")";
obj.onmousemove = function(e){
obj.style.opacity = 0.7;
//获取鼠标的位置(获取相对位置)
//鼠标在图片上的位置
var pageX_changed = e.pageX - 500;
var pageY_changed = e.pageY - 100;
//根据鼠标在改变宽高的图片的位置，计算鼠标在原图的位置
var pageX_start = parseInt(pageX_changed/width_changed*width_start);
var pageY_start = parseInt(pageY_changed/height_changed*height_start);
//定位一下div
new_div.style.display = "block";
new_div.style.position = "absolute";
new_div.style.left = parseInt(e.pageX - 100) + "px";
new_div.style.top = parseInt(e.pageY - 100) + "px";
new_div.style.overflow = "hidden";
new_div.style.width = "200px";
new_div.style.height = "200px";
//设置div的背景图片的位置
new_div.style.backgroundPosition = -(pageX_start-100) + "px " + -(pageY_start-100) + "px";
new_div.style.backgroundRepeat = "no-repeat";
}
obj.onmouseout = function(){
document.getElementById("showImg").style.display = "none";
obj.style.opacity = 1;
}
};
}
</script>
</body>
</html>
-------------------------------------------------------------
用于商品详情页的商品图放大镜
---------------------------------------------------------------
Imgzoom.prototype = {
constructor: Imgzoom,
init: function(){
this.createHtml();
this.bindEvents();
},
createHtml: function(){
if($('#'+this.previewId).length) return;
var $container = $(this.container);
!$container.length && console && console.log('can not find element, param "container" need checked.');
var $zoomDiv = $('<div id="' + this.previewId + '" class="zoomDiv" ><div class="zoomDiv-con"><img class="bigimg" width="100%" height="100%" /></div></div>');
$zoomDiv.css({"position":"absolute","top":$container.offset().top,"width":this.prevW, "height":this.prevH, "overflow":"hidden", "display":"none", "border":"1px solid #aaa", "zIndex":1000}).appendTo('body');
$container.css({"position":"relative"});
var $holder = $('<div class="zoomglass" id="zoomglass" />').css({"position":"absolute", "background":"#FFF27E", "top":$container.offset().top, "left":$container.offset().left, "zIndex":10, "opacity":0.5, "display":"none", "border":"1px dashed hotpink", "cursor":"crosshair", "width":this.prevW/this.scale, "height": this.prevH / this.scale}).appendTo('body');
if( this.dir == 'right'){
$zoomDiv.css({'left': $container.offset().left + $container.outerWidth() + this.margin});
}else if(this.dir == 'bottom'){
$zoomDiv.css({"top": $container.offset().top + $container.outerHeight() + this.margin, "left": $container.offset().left });
}
this.zoomDiv = $zoomDiv;
this.holder = $holder;
this.container = $(this.container);
},
bindEvents: function(){
var $simg, scale = this.scale, $zoomDiv = this.zoomDiv, $wrapper = $zoomDiv.find('.zoomDiv-con');
var $container = this.container, $holder = this.holder;
var offset = $container.offset();
var halfW = $holder.outerWidth()/2, halfH = $holder.outerHeight()/2;
var leftMin = offset.left+halfW, leftMax = leftMin+$container.width()-2*halfW;
var topMin = offset.top+halfH, topMax = topMin + $container.height()-2*halfH;
var leftBind = leftMin - halfW, rightBind = leftMax + halfW;
var topBind = topMin - halfH, btmBind = topMax + halfH;
var diffX= leftMax - leftMin, diffY = topMax -topMin;
var min = Math.min, max= Math.max;
// debugger;
$container.mouseenter(function(e){//初始化 大图
$holder.show(); $zoomDiv.show();
if($(e.target).hasClass('zoomimg')){
$simg = $(e.target);
$wrapper.css({"width": scale * $simg.outerWidth(), "height":scale * $simg.outerHeight()});//大图的大小
$zoomDiv.find('.bigimg').attr('src', $simg.attr('src')); //大图路径
}
});
$('body').mousemove(function(e){
// $holder.css({'left':e.pageX-halfW, 'top':e.pageY-halfH});
var x,y,position;
if(e.pageX < leftBind || e.pageX > rightBind || e.pageY < topBind || e.pageY > btmBind){
if(!$holder.ishide){ $holder.ishide=true; $holder.hide(); $zoomDiv.hide();}
return;
}else {
$holder.ishide = false;
x = min( max(e.pageX-halfW, leftBind), leftMax-halfW);
y = min( max(e.pageY-halfH, topBind), topMax-halfH);
$holder.css({"left":x,"top":y});
position = $holder.position();
$wrapper.css({"marginLeft":scale * (offset.left - position.left), "marginTop": scale * (offset.top - position.top)});
}
});
}
}
// $('.viewport').css({"outline":"1px solid red"});
var iz = new Imgzoom({scale:3, prevW:500, prevH:500});