JavaScript图片保持纵横比缩放代码。

 

 

function DrawImage(ImgD,maxSize)
{
      var image=new Image();
      image.src=ImgD.src;
      if(image.width>0  &&  image.height>0)
      {
          if(image.width/image.height>=1)
          {
             if(image.width>maxSize)
             {
                 ImgD.width=maxSize;
                 ImgD.height=(image.height*maxSize)/image.width;
             }
             else
             {
                 ImgD.width=image.width;
                 ImgD.height=image.height;
             }
          }
          else
          {
             if(image.height>maxSize)
             {
                ImgD.height=maxSize;
                ImgD.width=(image.width*maxSize)/image.height;
             }
             else
             {
                ImgD.width=image.width;
                ImgD.height=image.height;
             }
          }
     }
}