<%@ Page ContentType="image/jpeg"%>
<%@ Import Namespace="System.Drawing"%>
<%@ Import Namespace="System.Drawing.Imaging"%>
<Script Language="VB" Runat="Server">
	Sub Page_Load(Sender As Object,E as Eventargs)
		'這里隨機生成一個1000到9999之間的整數(shù),并將其轉(zhuǎn)化為字符串,然后將其保存在Session中
		Dim numTemp As String
		Dim rnd As New Random										'定義一個隨機數(shù)對象
		numTemp=rnd.Next(1000,9999).ToString						'生成隨機數(shù)并轉(zhuǎn)化成字符串
		Session("numValidate")=numTemp								'保存到Session中
		'下面建立一個圖像，并在上面寫字
		Dim bmp As New Bitmap(50,20,PixelFormat.Format32bppArgb)	'建立Bitmap對象
		Dim grh As Graphics = Graphics.FromImage(bmp)				'建立Graphics對象	
		grh.Clear(Color.Gray)										'填充灰色背景
		grh.DrawString(numTemp,new Font("宋體",14),Brushes.Blue,0,0)	'在圖像上寫字
		'將生成圖片以Jpeg格式顯示在頁面上
		bmp.Save(Response.OutputStream,ImageFormat.Jpeg)
	End Sub
</Script>