求教各位高手，如何让定了长宽的img图片不拉伸变形？

Question

<img id="showimg" name="showimg" alt="默认头像" src=""/>，求教各位高手，如何让定了长宽的img图片不拉伸变形？让它自动按比例在长宽区域内显示？

Answer 1

  function   DrawImage(ImgD,s_width,s_height)
    {   
    var   image=new   Image();     
    var   iwidth   =   s_width;     //定义允许图片宽度     
    var   iheight   =   s_height;     //定义允许图片高度     
    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;     
      }     
      ImgD.alt=image.width+"×"+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;     
      }     
      ImgD.alt=image.width+"×"+image.height;     
      }     
    }     
  }图片的onload调用这方法

Answer 2

img{width:100%!important;height:auto!important}