Google阅读器身份验证 - 添加Feed时出现401错误

Question

  

可能重复：
  Error in accessing google reader's Endpoints API

我正在尝试编写一个小应用程序来向Google阅读器帐户添加Feed。登录似乎工作正常但是当我尝试添加一个feed时，我收到401 Unauthorized错误。下面是GR对象。我正在使用它。

class GR
{
    private string _auth = null;
    private string _sid = null;
    private string _token = null;
    private Cookie _cookie = null;

    private string _username;
    private string _password;

    private void connect()
    {
        initToken();
    }

    private void initToken()
    {
        initSid();
        _cookie = new Cookie("SID", _sid, "/", ".google.com");

        string url = "https://www.google.com/reader/api/0/token";

        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
        req.Method = "GET";
        req.ContentType = "application/x-www-form-urlencoded";
        req.Headers.Add("Authorization", "GoogleLogin auth=" + _auth + "");

        HttpWebResponse response = (HttpWebResponse)req.GetResponse();
        using (Stream stream = response.GetResponseStream())
        {
            StreamReader r = new StreamReader(stream);
            _token = r.ReadToEnd();
        }
    }

    private void initSid()
    {
        string requestUrl = string.Format("https://www.google.com/accounts/ClientLogin?accountType=GOOGLE&service=reader&Email={0}&Passwd={1}", _username, _password);
        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(requestUrl);
        req.Method = "GET";

        HttpWebResponse response = (HttpWebResponse)req.GetResponse();
        using (Stream stream = response.GetResponseStream())
        {
            StreamReader r = new StreamReader(stream);

            /* TODO : Use propper SubString & IndofOf over Split & Replace */
            string cSID = "";
            string cLSID = "";
            string cAUTH = "";

            foreach (string cLine in r.ReadToEnd().Split('\n'))
            {
                if (cLine.StartsWith("SID=")) { cSID = cLine.Replace("SID=", ""); }
                if (cLine.StartsWith("LSID=")) { cLSID = cLine.Replace("LSID=", ""); }
                if (cLine.StartsWith("Auth=")) { cAUTH = cLine.Replace("Auth=", ""); }
            }

            _sid = cSID;
            // _lsid = cLSID;
            _auth = cAUTH;
        }
    }

    private HttpWebResponse httpGet(string requestUrl, string getArgs)
    {
        string url = string.Format("{0}?{1}", requestUrl, getArgs);

        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
        request.Method = "GET";
        request.ContentType = "application/x-www-form-urlencoded";
        request.Headers.Add("Authorization", "GoogleLogin auth=" + _auth + "");
        return (HttpWebResponse)request.GetResponse();
    }

    private HttpWebResponse httpPost(string requestUrl, string postArgs)
    {
        byte[] buffer = Encoding.GetEncoding(1252).GetBytes(postArgs);

        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(requestUrl);
        request.Method = "POST";
        request.CookieContainer = new CookieContainer();
        request.CookieContainer.Add(_cookie);
        request.ContentType = "application/x-www-form-urlencoded";
        request.ContentLength = buffer.Length;

        Stream PostData = request.GetRequestStream();

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

        try
        {
            return (HttpWebResponse)request.GetResponse();
        }
        catch
        {
            //handle error
            return null;
        }

    }

    public void Authenticate(string username, string password)
    {
        _username = username;
        _password = password;

        connect();
    }

    public bool AddFeed(string feedUrl)
    {
        string data = String.Format("quickadd={0}&T={1}", feedUrl, _token);
        string url = "http://www.google.com/reader/api/0/subscription/quickadd?client=scroll";

        HttpWebResponse response = httpPost(url, data);
        if (response == null) return false;
        return true;
    }

}

使用如下：

    private void button1_Click(object sender, EventArgs e)
    {
        GR gr = new GR();
        gr.Authenticate("username", "password");
        gr.AddFeed("http://feeds.bbci.co.uk/news/rss.xml");
    }

有人能看出我做错了什么吗？代码应该易于运行。只需将您的Google阅读器凭据插入到Authenticate方法调用中即可。