Facebook c# sdk FacebookClient 上的访问令牌签名无效答案

【问题标题】：Facebook c# sdk Invalid access token signature on FacebookClientFacebook c# sdk FacebookClient 上的访问令牌签名无效
【发布时间】：2013-02-20 23:37:52
【问题描述】：

我对 Facebook c# sdk 有疑问。

当我尝试连接 accesstoken 时，它会给出一条错误消息： (OAuthException) 访问令牌签名无效

我的网址是：

https://www.facebook.com/dialog/oauth?client_id=" + _appid + "&redirect_uri=http://localhost:51656/Register.aspx?scope=email,publish_stream,offline_access,create_event,user_about_me,user_activities,user_birthday,user_education_history,user_events,user_groups,user_interests,user_likes ,user_location,user_notes,user_religion_politics,user_relationship_details,user_photos,user_status

我的代码是：

    string _code ="";
    string _appid = "184604574912126";
    string _accesstoken;

    protected void Page_Load(object sender, EventArgs e)
    {
       if (Request.QueryString["code"] != null)
        {
            _code = Request.QueryString["code"].ToString();
        }
        if (_code != "")
        {
           _accesstoken = _appid + "|" + _code;
           vFB = new FacebookClient(_accesstoken);               
        }
        try
        {
            JsonObject vmyobject = (JsonObject)vFB.Get("/me");
        this line giving exaption.
     }

我错过了什么？

【问题讨论】：

标签： facebook-c#-sdk

【解决方案1】：

获取访问令牌的方式不对请看这段代码

        string AP_ID = System.Configuration.ConfigurationManager.AppSettings["FacebookAppID"];
    string client_secret = System.Configuration.ConfigurationManager.AppSettings["FacebookAppSecret"];
    string mywebsite = System.Configuration.ConfigurationManager.AppSettings["FacebookAppSecret"];
    string oathPage = System.Configuration.ConfigurationManager.AppSettings["PostAuthorizeRedirectURL"]; 
    string redirect_uri = mywebsite + oathPage;
                string code = Page.Request.QueryString["code"];
            string link = string.Format("https://graph.facebook.com/oauth/access_token?client_id={0}&code={1}&client_secret={2}&redirect_uri={3}", AP_ID, code, client_secret, redirect_uri);
            WebClient webq = new WebClient();
            string access_token = webq.DownloadString(link);
            int pos2 = access_token.IndexOf("&expires");
            if (pos2!=-1)
                access_token = access_token.Substring(13, pos2 - 13);
            else access_token = access_token.Substring(13, access_token.Length-13);

【讨论】：

【解决方案2】：

使用此方法从代码中获取有效的access_token：

 public string GetAccessTokenFromCode(string AppID, string AppSecret, string RedirectURL, string Code)
{
WebClient wc = new WebClient();
string u2 = "https://graph.facebook.com/oauth/access_token?client_id=" + AppID + "&redirect_uri=" + RedirectURL + "&client_secret=" + AppSecret + "&code=" + Code + "&state=anytexthere";
string access = wc.DownloadString(u2);
access = access.Substring(access.IndexOf("access_token") + 13);
if (access.Contains("&"))
{
string accesstoken = access.Substring(0, access.IndexOf("&"));
return accesstoken;
}

return access;

}

【讨论】：