ASP.NET获取上传图片的大小

1.采用客户端javascript可以取得图片大小 
<input id="FileUpload" type="file" size="30" name="FileUpload" onpropertychange="javascript:img2.src=this.value;"> 
<img id="img2" src="" style="visibility:hidden;position:absolute;top=-10000"/> 
<input type="button" value="获取" onclick="javascript:abc();">

<script type="text/javascript">
        function abc() {
            alert(img2.width);
        }
    </script>

2.采用流取得图片大小　 
Stream stream=file.PostedFile.InputStream; 
System.Drawing.Image image=System.Drawing.Image.FromStream(stream);

int picWidth= image.Width;
int picheight= image.Height;
3.使用文件得到图片大小 
System.Drawing.Image image=System.Drawing.Image.FromFile（图片路径）

int picWidth= image.Width;
int picheight = image.Height;