c# - 检索和设置 cookie

Question

我正在尝试连接到一个使用 cookie 的网站。我的登录如下:

        private void button1_Click(object sender, EventArgs e)
    {
        try
        {
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(baseurl);

            req.Referer = referer;
            req.AllowAutoRedirect = true;
            req.KeepAlive = true; 
            req.Method = "POST";
            req.ContentType = "application/x-www-form-urlencoded";
            byte[] postbuf = Encoding.ASCII.GetBytes(login);
            req.ContentLength = postbuf.Length;
            Stream rs = req.GetRequestStream();
            rs.Write(postbuf, 0, postbuf.Length);
            rs.Close();

            cookie = req.CookieContainer = new CookieContainer();

            WebResponse resp = req.GetResponse();

            string s = "";
            foreach (Cookie c in cookie.GetCookies(req.RequestUri))
            {
                s += ("Cookie['" + c.Name + "']: " + c.Value);
            }
            textBox1.Text = s;

            resp.Close();
        }
        catch (Exception ex)
        {
            System.Diagnostics.Debug.WriteLine(ex);
        }
    }

cookie 有 2 个带值的键。然后我尝试向该网站发送一个帖子请求，如下所示:

        private void button2_Click(object sender, EventArgs e)
    {
        try
        {
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(search);

            req.Referer = referer;
            req.AllowAutoRedirect = true;
            req.KeepAlive = true;
            req.CookieContainer = cookie;
            StreamReader reader = new StreamReader(req.GetResponse().GetResponseStream());

            if (reader != null)
            {
                string data = reader.ReadToEnd();
                reader.Close();

                textBox1.Text = data;
            }
        }
        catch (Exception ex)
        {
            System.Diagnostics.Debug.WriteLine(ex);
        }
    }

但是我得到一个错误，它无法验证。当我使用 firefox 登录时，我看到 cookie 包含更多条目。

我的代码有什么问题？

Answer 1

我认为您的错误在于以下行:

cookie = req.CookieContainer = new CookieContainer();

每次写入请求流后，您都在实例化一个新的 cookie 容器。

因为 cookie 是一个全局变量，它只初始化一次，例如在你写流之前说它声明和设置它的地方:

req.CookieContainer = cookie;
rs.Write(postbuf, 0, postbuf.Length);