asp.net生成缩略图

asp.net生成缩略图
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>