#div1 {
width:300px;
height:300px;
position:relative;
margin:30px auto 0px;
}
#div1 img{
width: 300px;
}
#div1 span {
width:150px;
height:150px;
background:red;
position:absolute;
left:0px;
top:0px;
display:none;
opacity:0.2;
}
.show {
width:100%;
height:100%;
background:red;
position:absolute;
left:0px; top:0px;
z-index:10px;
opacity:0.1;
}
#div2 {
width:300px;
height:300px;
position:relative;
top: -300px;
left: 300px;
display:none;
overflow:hidden;
margin:0px auto 0px;
}
#img1 {
position:absolute;
}
// 加载完成后显示
window.onload=function () {
var oDiv=document.getElementById('div1');
var oShow=document.getElementsByClassName('show')[0];
var oSpan=document.getElementsByTagName('span')[0];
var oImg=document.getElementById('img1');
// parentNode获得父节点
oShow.onmouseover=function() {
oSpan.style.display='block';
oImg.parentNode.style.display='block';
};
oShow.onmouseout=function() {
oSpan.style.display='';
oImg.parentNode.style.display='';
};
// 放大器移动
oShow.onmousemove=function(ev) {
// 解决浏览器兼容问题
var oEvent=ev||event;
// 获得鼠标的位置
var x=oEvent.offsetX-oSpan.offsetWidth/2;
var y=oEvent.offsetY-oSpan.offsetHeight/2;
// console.log(oEvent.clientY);
// console.log(oDiv.offsetTop);
// console.log(oSpan.offsetHeight/2);
// console.log(oEvent.clientY);
if(x<0) {
x=0;
} else if(x>oShow.offsetWidth-oSpan.offsetWidth) {
x=oShow.offsetWidth-oSpan.offsetWidth;
} if(y<0) {
y=0;
} else if(y>oShow.offsetHeight-oSpan.offsetHeight) {
y=oShow.offsetHeight-oSpan.offsetHeight;
}
// 给选中框定位
oSpan.style.left=x+'px';
oSpan.style.top=y+'px';
// 给放大器定位
var percentX=x/(oShow.offsetWidth-oSpan.offsetWidth);
var percentY=y/(oShow.offsetHeight-oSpan.offsetHeight);
var oImgparent=oImg.parentNode;
oImg.style.left=-percentX*(oImg.offsetWidth-oImgparent.offsetWidth)+'px';
oImg.style.top=-percentY*(oImg.offsetHeight-oImgparent.offsetHeight)+'px';
};
};
