JavaScript scales images proportionally-JS Tutorial-php.cn

JavaScript scales images proportionally

高洛峰

Release： 2016-11-28 11:33:14

Original

1233 people have browsed it

js scales images in equal proportions. This function is very practical. When a web page loads a relatively large image, it often deforms the web page and makes the page ugly. So we thought of using JS to control the image beyond a certain range. pictures to stabilize the page layout. This code snippet completes this function, and the code is very concise and the effect is very good.

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<head>
<title>等比例缩放图片</title>
<script>
function DrawImage(ImgD,iwidth,iheight){    
    //参数(图片,允许的宽度,允许的高度)    
    var image=new Image();    
    image.src=ImgD.src;    
    if(image.width>0 && image.height>0){    
      if(image.width/image.height>= iwidth/iheight){    
          if(image.width>iwidth){      
              ImgD.width=iwidth;    
              ImgD.height=(image.height*iwidth)/image.width;    
          }else{    
              ImgD.width=image.width;      
              ImgD.height=image.height;    
          }    
      }else{    
          if(image.height>iheight){      
              ImgD.height=iheight;    
              ImgD.width=(image.width*iheight)/image.height;            
          }else{    
              ImgD.width=image.width;      
              ImgD.height=image.height;    
          }    
      }    
    }    
}   
</script>
</head>
<body>
<img src=http://up.2cto.com/2013/0803/20130803034531502.jpg" alt="自动缩放后的效果" width="100" height="100" onload="javascript：DrawImage(this,80,80)" />
</body>
</html>

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