用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 widthheight 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