Question

我正在使用C＃开发桌面应用程序。

访问https://www.facebook.com/dialog/oauth?client_id=123后，用户登录并将用户访问令牌附加到重定向uri。没问题，当登录页面显示在我的表单中的webbrowser控件中时，我可以从URL中提取令牌。

但这不是我想获得令牌的方式。我的问题是，有没有办法通过Graph API调用获取新创建的令牌？

因为我想在用户的标准浏览器中显示登录页面而不是在此嵌入式Web浏览器中。我获取用户访问令牌的所有努力都导致获取 app 访问令牌，在这种情况下这是无用的。

任何提示都表示赞赏。

Answer 1

//这是非常原始的，注意它是一个MVC3解决方案，但它在C＃中，我希望它有所帮助。 //它基本上是FB上用于'Server Side Flow'的PHP示例的C＃版本 //我已经有一段时间了，不得不经历一些痛苦 //请注意我读到的有关这两个//请求的redirect_uri必须相同的错误 //还读到如果redirect_uri没有以'/'结尾，则有人有问题 //如果你有任何问题，请回复，因为我刚刚开始这个项目，我将尝试//合并C＃FaceBook SDK

public class AccountController : Controller
    {
        // LoginWithFaceBook
        // First Contact with FB - oauth?client_id ... redirect_uri = /Account/FacebookLinker 
        // according to a bug files on FB redirect_uri MUST BE SAME FOR both trips ( to get the 'code' then exchange the code for 'access_token'
        public ActionResult ConnectFaceBookAccount()
        {
            string APP_ID = HttpContext.Application["FacebookAppId"].ToString();
            string redirect_uri = HttpContext.Application["FacebookOAuthRedirect"].ToString();
            string state = HttpContext.Application["state_guid"].ToString();
            // in this View I simply link to this URL
            ViewBag.FaceBookOAuthUrl = "https://www.facebook.com/dialog/oauth?client_id=" + APP_ID + "&redirect_uri="+redirect_uri+"&state=" + state+"&display=popup";


            return View();
        }

        // Account/FacebookLinker
        //  redirect_uri for both getting 'code' and exchanging for 'access_token'
        public ActionResult FacebookLinker()
        {
            if (!Request.IsAuthenticated)
            {
                Response.Redirect("/Account/LogOn");
            }
            // Per FB DOC, Make sure 'state' var returned is same one you sent to reduce chance of Cross Site Forgery
            if (Request.QueryString["state"].ToString() == HttpContext.Application["state_guid"].ToString())
            {
                try
                {

                    string FBcode = Request.QueryString["code"].ToString();
                    string APP_ID = HttpContext.Application["FacebookAppId"].ToString();
                    string APP_SECRET = HttpContext.Application["FacebookAppSecret"].ToString();
                    string redirect_uri = HttpContext.Application["FacebookOAuthRedirect"].ToString();


                  string FBAccessUrl = "https://graph.facebook.com/oauth/access_token?client_id=" + APP_ID + "&redirect_uri=" + redirect_uri + "&client_secret=" + APP_SECRET + "&code=" + FBcode;


                string accessToken = null;
                // Send the request to exchange the code for access_token
                var accessTokenRequest = System.Net.HttpWebRequest.Create(FBAccessUrl);
                HttpWebResponse response = (HttpWebResponse) accessTokenRequest.GetResponse();

                 // handle response from FB 
                 // this will not be a url with params like the first request to get the 'code'
                Encoding rEncoding = Encoding.GetEncoding(response.CharacterSet);

                using(StreamReader sr = new StreamReader(response.GetResponseStream(),rEncoding))
                {
                    // parse the response to get the value of the 'access_token'
                    accessToken = HttpUtility.ParseQueryString(sr.ReadToEnd()).Get("access_token"); 
                }
                    //TODO
                    // Add to the accessToken for the Logged in User.Identity to a FBUSERS Model
                    // WHen someone Logs in Check to see if they are also in FB
                    // ON Login Page add option to login with FaceBook


                  return View();

                }
                catch (Exception exp)
                {
                    // try to get token failed

                }
            }
            else
            {
                 // state var form FB did not match state var sent

            }
            return View();
        }

Answer 2

我认为这可以通过URL协议处理程序实现;

创建自定义网址协议处理程序（MSDN: Registering an Application to a URL Protocol）
创建一个将用户访问令牌传递给您的网址处理程序的Facebook页面（例如myfbapp://accesstoken/{token}）
将oauth redirect_uri设置为您的脸谱页
在您的应用程序中解析访问令牌

C＃：获取用户访问令牌

2 个答案: