(转)按比例缩放图片

看到海东兄的按比例缩放图片 ，我就把我写的js版本的也拿出来show一下，哈哈！
js版本：

function resizeImage(obj, MaxW, MaxH)
{
 var imageObject = obj;
    var state = imageObject.readyState;
 if(state!='complete')
 {
        setTimeout("resizeImage("+imageObject+","+MaxW+","+MaxH+")",50);
  return;
    }
    var oldImage = new Image();
    oldImage.src = imageObject.src;
    var dW = oldImage.width;
    var dH = oldImage.height;
    if(dW>MaxW || dH>MaxH)
 {
        a = dW/MaxW; b = dH/MaxH;
        if( b>a ) a = b;
        dW = dW/a; dH = dH/a;
    }
    if(dW > 0 && dH > 0)
 {
        imageObject.width = dW;
  imageObject.height = dH;
 }
}

使用很简单：<img src="../pic.jpg" onload='resizeImage(this,60,90)> 就OK了；同时也附上C#版本的

C#版本---海东兄 http://www.cnblogs.com/ghd258/archive/2005/11/07/270447.html

1/**//// <summary>
 2        /// 按比例缩放图片
 3        /// </summary>
 4        /// <param name="imgUrl">图片的路径</param>
 5        /// <param name="imgHeight">图片的高度</param>
 6        /// <param name="imgWidth">图片的宽度</param>
 7        /// <returns></returns>
 8        public static string GetImageSize(string imgUrl,int imgHeight,int imgWidth)
 9        {
10            string fileName = System.Web.HttpContext.Current.Server.MapPath(imgUrl);
11            string strResult = string.Empty;
12            if(System.IO.File.Exists(fileName) && imgHeight != 0 && imgWidth != 0)
13            {
14                decimal desWidth;decimal desHeight;                                            //目标宽高
15                System.Drawing.Image objImage = System.Drawing.Image.FromFile(fileName);
16                decimal radioAct = (decimal)objImage.Width/(decimal)objImage.Height;        //原始图片的宽高比
17                decimal radioLoc = (decimal)imgWidth/(decimal)imgHeight;                    //图片位的宽高比
18                if(radioAct > radioLoc)                                                        //原始图片比图片位宽
19                {        
20                    decimal dcmZoom = (decimal)imgWidth/(decimal)objImage.Width;
21                    desHeight = objImage.Height*dcmZoom;
22                    desWidth = imgWidth;
23                }
24                else
25                {
26                    decimal dcmZoom = (decimal)imgHeight/(decimal)objImage.Height;
27                    desWidth = objImage.Width*dcmZoom;
28                    desHeight = imgHeight;
29                }
30                objImage.Dispose();                //释放资源
31                strResult = "width=\"" + Convert.ToString((int)desWidth) + "\" height=\""
32                    + Convert.ToString((int)desHeight) + "\" ";
33            }
34            return strResult;
35        }






<script language="javascript">
function changeImg(mypic){
var xw=160;
var xl=180;

var width = mypic.width;
var height = mypic.height;
var bili = width/height;

var A=xw/width;
var B=xl/height;

if(!(A>1&&B>1))
{
if(A<B)
{
mypic.width=xw;
mypic.height=xw/bili;
}
if(A>B)
{
mypic.width=xl*bili;
mypic.height=xl;
}
}
}
</script>
<img src="sh180.jpg" onload="changeImg(this)">