http://www.cnblogs.com/xiaochaohuashengmi/archive/2010/06/01/1749571.html
如果图片太大,刷新页面的话会有大图跳转,我们先用min-width,min-height来控制图片缩小到一定程度,在进行二次缩放
Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>最新javascript自动按比例显示图片,按比例压缩图片显示</title>
<script type="text/javascript">
function AutoResizeImage(maxWidth,maxHeight,objImg){
var img = new Image();
img.src = objImg.src;
var hRatio;
var wRatio;
var Ratio = 1;
var w = img.width;
var h = img.height;
wRatio = maxWidth / w;
hRatio = maxHeight / h;
if (maxWidth ==0 && maxHeight==0){
Ratio = 1;
}else if (maxWidth==0){//
if (hRatio<1) Ratio = hRatio;
}else if (maxHeight==0){
if (wRatio<1) Ratio = wRatio;
}else if (wRatio<1 || hRatio<1){
Ratio = (wRatio<=hRatio?wRatio:hRatio);
}
if (Ratio<1){
w = w * Ratio;
h = h * Ratio;
}
objImg.height = h;
objImg.width = w;
}
</script>
</head>
<body>
<br />
原图显示(534 X 800)<br />
onload="AutoResizeImage(0,0,this)<br />
<a href="http://p.blog.csdn.net/images/p_blog_csdn_net/feng_sundy/421506/o_09925c7bcead8c60f683298dacf497a6.jpg" target="_blank"><img src="http://p.blog.csdn.net/images/p_blog_csdn_net/feng_sundy/421506/o_09925c7bcead8c60f683298dacf497a6.jpg" border="0" width="0" height="0" onload="AutoResizeImage(0,0,this)" alt="534 X 800"/></a><br/><br />
1.按宽度250压缩,不限制高度 按比例压缩<br />
onload="AutoResizeImage(250,0,this)"<br />
<a href="http://blog.csdn.net/feng_sundy/archive/2008/06/19/2566028.aspx" target="_blank"><img src="http://p.blog.csdn.net/images/p_blog_csdn_net/feng_sundy/421506/o_09925c7bcead8c60f683298dacf497a6.jpg" border="0" width="0" height="0" onload="AutoResizeImage(250,0,this)" alt="250 X 374"/></a><br /><br />
2.按高度250压缩,不限制宽度 按比例压缩<br />
onload="AutoResizeImage(0,250,this)"<br />
<a href="http://blog.csdn.net/feng_sundy/archive/2008/06/19/2566028.aspx" target="_blank"><img src="http://p.blog.csdn.net/images/p_blog_csdn_net/feng_sundy/421506/o_09925c7bcead8c60f683298dacf497a6.jpg" border="0" width="0" height="0" onload="AutoResizeImage(0,250,this)" alt="166 X 250"/></a><br /><br />
3.按高度250宽度250 按比例压缩<br />
onload="AutoResizeImage(250,250,this)"<br />
<a href="http://blog.csdn.net/feng_sundy/archive/2008/06/19/2566028.aspx" target="_blank"><img src="http://p.blog.csdn.net/images/p_blog_csdn_net/feng_sundy/421506/o_09925c7bcead8c60f683298dacf497a6.jpg" border="0" width="0" height="0" onload="AutoResizeImage(250,250,this)" alt="200 X 300"/></a><br /><br />
4.高宽不等比例压缩 (400 X 512),此时高度不变,会自动按高度的比例压缩。<br />
onload="AutoResizeImage(400,512,this)"<br />
<a href="http://blog.csdn.net/feng_sundy/archive/2008/06/19/2566028.aspx" target="_blank"><img src="http://p.blog.csdn.net/images/p_blog_csdn_net/feng_sundy/421506/o_09925c7bcead8c60f683298dacf497a6.jpg" border="0" width="0" height="0" onload="AutoResizeImage(400,512,this)" alt="341 X 512"/></a><br /><br />
5.高宽不等比例压缩 (300 X 600),此时宽度不变,会自动按宽度的比例压缩。<br />
onload="AutoResizeImage(300,600,this)"<br />
<a href="http://blog.csdn.net/feng_sundy/archive/2008/06/19/2566028.aspx" target="_blank"><img src="http://p.blog.csdn.net/images/p_blog_csdn_net/feng_sundy/421506/o_09925c7bcead8c60f683298dacf497a6.jpg" border="0" width="0" height="0" onload="AutoResizeImage(300,600,this)" alt="300 X 449"/></a><br /><br />
6.如果图片本来的高度和宽度小于压缩的最大高度和宽度,则不会拉大显示图片(按原图显示)<br />
原图444 x 207,压缩为 500 x 600,将保持原图显示<br />
onload="AutoResizeImage(500,600,this)"<br />
<a href="http://blog.csdn.net/feng_sundy/archive/2008/06/19/2566028.aspx" target="_blank"><img src="http://p.blog.csdn.net/images/p_blog_csdn_net/feng_sundy/242776/o_20070410_b7409cd284a0f799a357uePcEFa6ty0X.jpg" border="0" width="0" height="0" onload="AutoResizeImage(500,600,this)" alt="444 X 207"/></a><br /><br />
</body>
</html>
另一种方法
http://blog.csdn.net/luyang1016/article/details/7212154
- <!DOCTYPE html>
- <html>
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
- <title>按比例自动缩放图片</title>
- <script src="./js/jquery-1.6.2.js"></script>
- <script>
- /// <summary>
- /// 调整图片大小并居中
- /// </summary>
- /// <remarks>
- /// <param>图片对象</param>
- /// <param>容器最大宽度</param>
- /// <param>容器最大高度</param>
- /// </remarks>
- var adjustImgSize = function(img, boxWidth, boxHeight) {
- // var imgWidth=img.width();
- // var imgHeight=img.height();
- // 上面这种取得img的宽度和高度的做法有点儿bug
- // src如果由两个大小不一样的图片相互替换时,上面的写法就有问题了,换过之后的图片的宽度和高度始终取得的还是换之前图片的值。
- // 解决方法:创建一个新的图片类,并将其src属性设上。
- var tempImg = new Image();
- tempImg.src = img.attr('src');
- var imgWidth=tempImg.width;
- var imgHeight=tempImg.height;
- //比较imgBox的长宽比与img的长宽比大小
- if((boxWidth/boxHeight)>=(imgWidth/imgHeight))
- {
- //重新设置img的width和height
- img.width((boxHeight*imgWidth)/imgHeight);
- img.height(boxHeight);
- //让图片居中显示
- var margin=(boxWidth-img.width())/2;
- img.css("margin-left",margin);
- }
- else
- {
- //重新设置img的width和height
- img.width(boxWidth);
- img.height((boxWidth*imgHeight)/imgWidth);
- //让图片居中显示
- var margin=(boxHeight-img.height())/2;
- img.css("margin-top",margin);
- }
- };
- // 本机能的js事件
- $(function() {
- // 图像加载完成之后,调整图片大小
- $('#img1').load(function() {
- adjustImgSize($(this), $(this).parent().width(), $(this).parent().height());
- });
- });
- </script>
- </head>
- <body>
- <div id="imgBox" style="500px; height:200px; background:#cccccc">
- <img id="img1" alt="" src="./image/test.jpg" />
- </div>
- </body>
- </html>