JavaScript圖片保持縱橫比縮放代碼。

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;

             }

          }

     }

}