急求验证码参数传递问题

ykwang 2004-05-12 09:07:16

我用如下语句产生验证码
If Page.IsPostBack = False Then
lsb = Trim(Str(Int(raa.Next(100, 9999))))
Response.ContentType = "image/gif"
getimage(lsb).Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Gif)
Response.Cookies("loginyz").Value = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(lsb, "MD5")
Response.Cookies("loginyz").Expires = Now.AddDays(1)
End If

Private Function getimage(ByVal s As String) As Bitmap
Dim b As Bitmap = New Bitmap(1, 1)
Dim afont As Font = New Font("黑体", 16, System.Drawing.GraphicsUnit.Point)
Dim agraphic As Graphics = Graphics.FromImage(b)
b = New Bitmap(CInt(agraphic.MeasureString(s, afont).Width), CInt(agraphic.MeasureString(s, afont).Height))
agraphic = Graphics.FromImage(b)
agraphic.Clear(Color.Black)
agraphic.TextRenderingHint = TextRenderingHint.AntiAlias
agraphic.DrawString(s, afont, New SolidBrush(Color.White), 0, 0)
agraphic.Flush()
Return b

End Function

假设这页是名字是loginyz.aspx
我在登陆页的 IMAGE1的imageURL是loginyz.aspx
我用
Response.Cookies("loginyz").Value = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(lsb, "MD5")
Response.Cookies("loginyz").Expires = Now.AddDays(1)
将图片的随机数用MD5加密存入COOKIE.
但为什么有些电脑能正常使用,有些不能.

我把Response.Cookies("loginyz").Value = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(lsb, "MD5")
Response.Cookies("loginyz").Expires = Now.AddDays(1)
换成SESSION存储,为什么SESSION的值都为空?
请问有什么好的办法?

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