c# - 为什么我在发布到 Google Reader API 时收到 401(未经授权)错误？

Question

我正在尝试使用来自 this page 的信息与 Google 阅读器(未记录/非官方)API 交互.我的第一步是获取 SID 和 token ，这工作正常，但我似乎无法在不收到 401 错误的情况下发布任何内容。

这是我用来获取我的 SID 和 token 的代码:

static string getSid()
    {
        HttpWebRequest req = (HttpWebRequest)WebRequest.Create("https://www.google.com/accounts/ClientLogin?service=reader&Email=username&Passwd=password");
        req.Method = "GET";
        string sid;

        HttpWebResponse response = (HttpWebResponse)req.GetResponse();
        using (var stream = response.GetResponseStream())
        {
            StreamReader r = new StreamReader(stream);
            string resp = r.ReadToEnd();

            int indexSid = resp.IndexOf("SID=") + 4;
            int indexLsid = resp.IndexOf("LSID=");
            sid = resp.Substring(indexSid, indexLsid - 5);

            return sid;
        }
    }

并生成 cookie 并获取 token :

    static Cookie getCookie(string sid)
    {
        Cookie cookie = new Cookie("SID", sid, "/", ".google.com");
        return cookie;
    }

    static string getToken(string sid, Cookie cookie)
    {
        string token;
        string url = "http://www.google.com/reader/api/0/token";

        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
        req.CookieContainer = new CookieContainer();
        req.CookieContainer.Add(cookie);

        HttpWebResponse response = (HttpWebResponse)req.GetResponse();
        using (var stream = response.GetResponseStream())
        {
            StreamReader r = new StreamReader(stream);
            token = r.ReadToEnd();
            return token;
        }
    }

现在，如果我尝试使用以下内容执行 POST(在此示例中，插入一个新标签)，我会收到 401 错误。

    static void insertTag(string tag, Cookie cookie)
    {
        string result = "";
        string data = Uri.EscapeDataString("a="+tag+"&T=" + Program.token);

        byte[] buffer = Encoding.GetEncoding(1252).GetBytes(data);
        HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create
            ("http://www.google.com/reader/api/0/edit-tag?client=-");
        WebReq.Method = "POST";

        WebReq.Credentials = new NetworkCredential("username", "password");


        WebReq.ContentType = "application/x-www-form-urlencoded";
        WebReq.ContentLength = buffer.Length;

        Stream PostData = WebReq.GetRequestStream();

        PostData.Write(buffer, 0, buffer.Length);
        PostData.Close();

        HttpWebResponse WebResp = (HttpWebResponse)WebReq.GetResponse();
        Stream Answer = WebResp.GetResponseStream();
        StreamReader _Answer = new StreamReader(Answer);
        result = _Answer.ReadToEnd();

        if (result.Length < 0)
            result = "";
    }

错误发生在行 Stream Answer = WebResp.GetResponseStream();

Answer 1

您需要仔细检查您是否设置了用户代理。我之前没有设置它时遇到过同样的问题。

例如:

WebClient client = new WebClient();

client.Headers.Add("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)");

或:MSDN Link

myHttpWebRequest=(HttpWebRequest)WebRequest.Create("http://www.contoso.com");
myHttpWebRequest.UserAgent="Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)";