当我们要上传图片的时候，往往需要生成缩略图，以往我们要使用第三方控件才能完成。在ASP.net中用下面方法轻松搞定
  <script language="VB" runat="server">
  Sub Page_Load(sender As Object, e As EventArgs)
  
  
  Dim image,aNewImage As System.Drawing.Image
  dim width,height,newwidth,newheight as integer
  Dim callb As System.Drawing.Image.GetThumbnailImageAbort
  
  
  ''生成缩略图
  image=System.Drawing.Image.FromFile(Server.MapPath("classpic/"+"rs1.jpg"))
  width=image.Width
  height=image.height
  if width>height then
  newwidth=110
  newheight=image.height/image.Width*newwidth
  else
  newheight=110
  newwidth=image.Width/image.height*newheight
  end if
  
  
  aNewImage=image.GetThumbnailImage(newwidth,newheight,callb,new System.IntPtr())
  aNewImage.Save(Server.MapPath("smallpic/"+"rs1.gif"))
  image.Dispose()
  
  
  End Sub
  </script>