【JS控制图片显示的大小(图片等比例缩放)】

效果:

 

代码:

<!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>

 

posted on 2016-07-31 11:46  ultrastrong  阅读(256)  评论(0编辑  收藏  举报