protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { string strCaptchaImageText = YDCode.Rand.Str(5).Trim(); Session["CaptchaImageText"] = strCaptchaImageText; string CaptchaImageText = strCaptchaImageText; MemoryStream ms = Rand.CreateCodeImg(CaptchaImageText); Response.ClearContent(); Response.ContentType = "image/Gif"; Response.BinaryWrite(ms.ToArray()); } }