奇妙的Javascript图片放大镜_图象特效

　　制作思路：“放大镜”后有一幅背景图，它是“放大了”的图的原本。我们通过移动“放大镜”时适当调整背景图的位置，使它显示的刚好是需要要放大的部分。

　　效果演示： (点这里在新窗口中查看)

　　制作步骤：

　　１）先准备两幅内容相同尺寸不同的图片，这里我们找了一个400×300像素的缩略图small_hill.gif，一个800×600像素的大图big_hill.gif。然后再准备一个“放大镜”的图片，注意它中间部分必须是透明的，这里我们准备了一个绿色的方框 viewer.gif。

　　２）编写如下的代码：

　　以下是两幅图的代码，都它们作为层。第一幅是缩略图，第二幅是“放大镜”，首先将它的背景移到不可见的地方； 其中“ onclick="moveme=!moveme" ”表示每次点击它都改变“moveme”的布尔值。

"small_hill.gif"https://www.gxlcms.com/ id=https://www.gxlcms.com/"bgLayer"https://www.gxlcms.com/ style=https://www.gxlcms.com/"position:absolute; left:150px; top:50px;"https://www.gxlcms.com/>
"viewer.gif"https://www.gxlcms.com/ id=https://www.gxlcms.com/"myviewer"https://www.gxlcms.com/ onclick=https://www.gxlcms.com/"moveme=!moveme"https://www.gxlcms.com/ onmousemove=https://www.gxlcms.com/"viewit(this)"https://www.gxlcms.com/
style=https://www.gxlcms.com/"left:0;top:0;background-repeat:no-repeat; background-position:2000px 2000px;position:absolute;"https://www.gxlcms.com/>https://www.gxlcms.com/

以下是JavaScript脚本:

https://www.gxlcms.com/

varhttps://www.gxlcms.com/ viewer_bgcolor=https://www.gxlcms.com/"#FFFFFF"https://www.gxlcms.com/; //放大镜的背景色，建议设成和网页背景色相同。 https://www.gxlcms.com/
varhttps://www.gxlcms.com/ bigmap=https://www.gxlcms.com/"big_hill.gif"https://www.gxlcms.com/; //大图路径 https://www.gxlcms.com/

documenthttps://www.gxlcms.com/.allhttps://www.gxlcms.com/.myviewer.style.backgroundImage=https://www.gxlcms.com/'url('https://www.gxlcms.com/+https://www.gxlcms.com/bigmap+https://www.gxlcms.com/')'https://www.gxlcms.com/;
documenthttps://www.gxlcms.com/.allhttps://www.gxlcms.com/.myviewer.style.backgroundColor=https://www.gxlcms.com/viewer_bgcolor;
//因为大图作为背景无法设定和读取它的尺寸，只好把它的一个副本作为实图，但不可见： https://www.gxlcms.com/
documenthttps://www.gxlcms.com/.writehttps://www.gxlcms.com/(https://www.gxlcms.com/'+https://www.gxlcms.com/bigmap+https://www.gxlcms.com/'">'https://www.gxlcms.com/)https://www.gxlcms.com/;

varhttps://www.gxlcms.com/ moveme=https://www.gxlcms.com/falsehttps://www.gxlcms.com/; //该布尔值决定“放大镜”是否随鼠标移动，初始值为否 https://www.gxlcms.com/
functionhttps://www.gxlcms.com/ viewit(https://www.gxlcms.com/obj){https://www.gxlcms.com/
ifhttps://www.gxlcms.com/ (https://www.gxlcms.com/moveme){https://www.gxlcms.com/
//以下两行控制“放大镜”的移动： https://www.gxlcms.com/
obj.style.left=https://www.gxlcms.com/eventhttps://www.gxlcms.com/.x+https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.bodyhttps://www.gxlcms.com/.scrollLeft)https://www.gxlcms.com/-https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/obj.width)https://www.gxlcms.com//https://www.gxlcms.com/2https://www.gxlcms.com/;
obj.style.top=https://www.gxlcms.com/eventhttps://www.gxlcms.com/.y+https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.bodyhttps://www.gxlcms.com/.scrollTop)https://www.gxlcms.com/-https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/obj.height)https://www.gxlcms.com//https://www.gxlcms.com/2https://www.gxlcms.com/;

//以下几行调整当“放大镜”移动时其背景图的位置，使其中心移到缩略图的某点时，其背景图上相应的点也移动到其中心。
//其中Nx，Ny指大图宽和高分别是小图的几倍，bgx，bgy是背景图当移到的X,Y坐标。
https://www.gxlcms.com/ Nx=https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.allhttps://www.gxlcms.com/.getsize.width)https://www.gxlcms.com//https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.allhttps://www.gxlcms.com/.bgLayer.width)https://www.gxlcms.com/;
bgx=https://www.gxlcms.com/(https://www.gxlcms.com/-https://www.gxlcms.com/1https://www.gxlcms.com/)https://www.gxlcms.com/*https://www.gxlcms.com/(https://www.gxlcms.com/Nx-https://www.gxlcms.com/1https://www.gxlcms.com/)https://www.gxlcms.com/*https://www.gxlcms.com/(https://www.gxlcms.com/eventhttps://www.gxlcms.com/.x-https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.allhttps://www.gxlcms.com/.bgLayer.style.left)https://www.gxlcms.com/+https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.bodyhttps://www.gxlcms.com/.scrollLeft))https://www.gxlcms.com/-https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/obj.style.left)https://www.gxlcms.com/+https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.allhttps://www.gxlcms.com/.bgLayer.style.left)https://www.gxlcms.com/;

Ny=https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.allhttps://www.gxlcms.com/.getsize.height)https://www.gxlcms.com//https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.allhttps://www.gxlcms.com/.bgLayer.height)https://www.gxlcms.com/;
bgy=https://www.gxlcms.com/(https://www.gxlcms.com/-https://www.gxlcms.com/1https://www.gxlcms.com/)https://www.gxlcms.com/*https://www.gxlcms.com/(https://www.gxlcms.com/Ny-https://www.gxlcms.com/1https://www.gxlcms.com/)https://www.gxlcms.com/*https://www.gxlcms.com/(https://www.gxlcms.com/eventhttps://www.gxlcms.com/.y-https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.allhttps://www.gxlcms.com/.bgLayer.style.top)https://www.gxlcms.com/+https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.bodyhttps://www.gxlcms.com/.scrollTop))https://www.gxlcms.com/-https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/obj.style.top)https://www.gxlcms.com/+https://www.gxlcms.com/parseInthttps://www.gxlcms.com/(https://www.gxlcms.com/documenthttps://www.gxlcms.com/.allhttps://www.gxlcms.com/.bgLayer.style.top)https://www.gxlcms.com/;

obj.style.backgroundPosition=https://www.gxlcms.com/bgx+https://www.gxlcms.com/" "https://www.gxlcms.com/+https://www.gxlcms.com/bgy;
}
}https://www.gxlcms.com/
//--> https://www.gxlcms.com/
https://www.gxlcms.com/
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>放大镜</title> </head> <body bgcolor="#FFFFFF"> <center> --JS放大镜显示-- 单击"放大镜"开始浏览，再次单击停止。</center> <img src="http://www.softpure.com/soft/work/jsviewer/small_hill.gif" id="bgLayer" style="position:absolute; left:160px; top:50px;"> <img src="http://www.softpure.com/soft/work/jsviewer/viewer.gif" id="myviewer" onclick="moveme=!moveme" onmousemove="viewit(this)" style="background-repeat:no-repeat;background-position:2000px 2000px;position:absolute;"> var viewer_bgcolor="#FFFFFF"; //放大镜的背景色，建议设成和网页背景色相同。 var bigmap="http://www.softpure.com/soft/work/jsviewer/big_hill.gif"; //大图路径 document.all.myviewer.style.backgroundImage='url(/Uploads/'+bigmap+')'; document.all.myviewer.style.backgroundColor=viewer_bgcolor; document.write('<img id="getsize" style="position:absolute; left:-2000px; top:-2000px;" src="https://www.gxlcms.com/Uploads/'+bigmap+'">'); var moveme=false; function viewit(obj){ if (moveme){ obj.style.left=event.x+parseInt(document.body.scrollLeft)-parseInt(obj.width)/2; obj.style.top=event.y+parseInt(document.body.scrollTop)-parseInt(obj.height)/2; Nx=parseInt(document.all.getsize.width)/parseInt(document.all.bgLayer.width); bgx=(-1)*(Nx-1)*(event.x-parseInt(document.all.bgLayer.style.left)+parseInt(document.body.scrollLeft))-parseInt(obj.style.left)+parseInt(document.all.bgLayer.style.left); Ny=parseInt(document.all.getsize.height)/parseInt(document.all.bgLayer.height); bgy=(-1)*(Ny-1)*(event.y-parseInt(document.all.bgLayer.style.top)+parseInt(document.body.scrollTop))-parseInt(obj.style.top)+parseInt(document.all.bgLayer.style.top); obj.style.backgroundPosition=bgx+" "+bgy; }} </ script> </body> </html>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]