Facebook API：无法在 Android 上登录

我正在尝试使用 Facebook API 在 Android 上实现 Facebook 登录。我已经按照方法做了一切Facebook 登录流程 http://developers.facebook.com/docs/android/login-with-facebook/说。代码如下。

public class FBSignIn extends Fragment {
    private UiLifecycleHelper uiHelper;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        final View v = super.onCreateView(inflater, container, savedInstanceState);
        setTitle("Sign In");
        reloadTemplate();

        uiHelper = new UiLifecycleHelper(getActivity(), callback);
        uiHelper.onCreate(savedInstanceState);

        return v;
    }

    @Override
    public void onResume() {
        super.onResume();
        uiHelper.onResume();
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        uiHelper.onActivityResult(requestCode, resultCode, data);
    }

    @Override
    public void onPause() {
        super.onPause();
        uiHelper.onPause();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        uiHelper.onDestroy();
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        uiHelper.onSaveInstanceState(outState);
    }

    @Override
    public boolean executeCommand(BaseWebView webView, String command, String data) {

        if (command.equalsIgnoreCase("login")) {
            Session session = Session.getActiveSession();

            if (session != null && session.isOpened()) {
                loginWithFBToken(session.getAccessToken());
                return;
            }

            Session.openActiveSession(getActivity(), true, callback);
        }

        return true;
    }

    private Session.StatusCallback callback = new Session.StatusCallback() {
        @Override
        public void call(Session session, SessionState state, Exception exception) {
            onSessionStateChange(session, state, exception);
        }
    };

    private void onSessionStateChange(Session session, SessionState state, Exception exception) {
        if (state.isOpened()) {
            // Facebook logged in...

        } else if (state.isClosed()) {
            //Facebook logged out...
        }
    }

}

然而，之后Session.openActiveSession()打电话，在onSessionsStateChange()函数，我首先得到state == CLOSED_LOGIN_FAILED;之后第二次调用state == OPENING。所以它永远不会进入OPENED state.

这段代码有什么问题？我非常感谢你的帮助。

附：我已经注释掉了有关的所有内容uiHelper并且，在我的主要活动中，提供了重写的方法：

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
    }

现在第一个电话onSessionStateChange附带state == OPENING and exception == null。第二次通话附带state == CLOSED_LOGIN_FAILED and exception == Invalid access token。这意味着什么？

我已经解决了这个问题。原因是我们的应用程序以沙盒模式在Facebook中注册，只有某些用户可以使用Facebook登录。当我用其中一个帐户登录时，它起作用了。