用 JavaScript 实现网页图片等比例缩放

 <script language="JavaScript" type="text/javascript">
    <!--
    // 说明：用 JavaScript 实现网页图片等比例缩放
    // 整理：http://www.CodeBit.cn 
    function DrawImage(ImgD,FitWidth,FitHeight)
    {    
       var image=new Image();
       image.src=ImgD.src;    
       if(image.width>0 && image.height>0)
       {        
            if(image.width/image.height>= FitWidth/FitHeight)
            {            
                if(image.width>FitWidth)
                {               
                    ImgD.width=FitWidth;              
                      ImgD.height=(image.height*FitWidth)/image.width;
                }else
                {                
                   ImgD.width=image.width;
                   ImgD.height=image.height;
                               
                 }        
            }
             else
            {
                 if(image.height>FitHeight)
                 {                
                 ImgD.height=FitHeight;
                 ImgD.width=(image.width*FitHeight)/image.height;
                 }else
                 {
                  ImgD.width=image.width;
                  ImgD.height=image.height;
                             
                  }        
              }    
        }
    } //-->
  </script>

 

 

调用方式：
Code:

<img src="1148202890.jpg" alt="自动缩放后的效果" onload="javascript:DrawImage(this,200,200);" />

如果图片较大，建议在图片标签里面同时设置期望的图片大小，这样不会导致页面在加载中撑开，该大小不会影响最终缩放效果。可以修改上面的代码为：

Code:

<img src="1148202890.jpg" alt="自动缩放后的效果" width="200" height="200" onload="javascript:DrawImage(this,200,200);" />