resize image trong asp.net

   '------ tạo file img.aspx để lấy hình nhỏ--- 

<%@ Page Language=''VB'' %> 
<%@ import Namespace=''System.Drawing'' %> 
<%@ import Namespace=''System.io'' %> 
<%@ import Namespace=''System.Drawing.Imaging'' %> 
<script runat=''server''> 

function wh(byval old as point,thu as point) as point 
if old.x> old.y then 
wh.x=thu.x 
wh.y=(old.y / old.x)*thu.y 
end if 
if old.x < old.y then 
wh.y=thu.y 
wh.x=(old.x / old.y)*thu.x 
end if 
if old.x= old.y then 
wh.x=thu.x 
wh.y=thu.y 
end if 
end function 

function thumb(filename as string,byval s as integer) as bitmap 
Dim b As System.Drawing.image=System.Drawing.image.FromFile (server.mappath(filename)) 
dim c as new bitmap(s,s) 
dim p as point=wh(new point(b.width,b.height),new point(s,s)) 
c=b.GetThumbnailImage(p.x,p.y,nothing,nothing) 
return c 
b.dispose 
c.dispose 

end function 
Sub Page_Load(sender As Object, e As EventArgs) 
dim name as string=server.urldecode(request(''name'')) 
if name<>nothing then thumb(name,100).save (response.outputstream,imageformat.jpeg) else response.write(''thumbnail file by Panh'') ' số 100 là kich thước ảnh lúc thumb 
End Sub 

</script> 
<html> 
<head> 
</head> 
<body bgcolor=''silver''> 
<form runat=''server''> 
</form> 
</body> 
</html> 

ví dụ muốn tạo thumb ảnh ''loveyou.jpg'' thì ghi như sau <img src=img.aspx?name=loveyou.jpg> ---> tạo ra ảnh nhỏ mà nhẹ,nhanh . Tỉ lệ kich thứơc width, height như cũ 