如下的验证码生成与校验,部分用户反映无论如何都是验证码失效,但是部分用户正常

生成验证码时的代码

HttpCookie hc = context.Response.Cookies[cookieName];

if ( hc== null)       hc=new HttpCookie(cookieName);

hc.Value = outCodeToCookie;

hc.Expires = DateTime.Now.AddMilliseconds(1*60 * 1000); context.Response.AppendCookie(hc);

image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);

context.Response.ClearContent();

context.Response.Cache.SetCacheability(HttpCacheability.NoCache);

 context.Response.ContentType = "image/Jpeg";             context.Response.BinaryWrite(ms.GetBuffer());            

context.Response.Flush();

 校验的时候

HttpCookie cookie = HttpContext.Current.Request.Cookies[CookieName];
            if (cookie != null && !string.IsNullOrEmpty(cookie.Value))
            {
                if (输入正确)
                {
                   返回正确
                }
                else
                {返回错误}
                
            }
            return 验证码超时;