android - 为什么我的 facebook android sdk 登录被调用了两次？

Question

我正在使用 Facebook SDK，问题是 FormSubmit 函数运行了两次。它被 getView 函数调用，被 onCreateView 和 statusCallback 调用，如何解决？

public class Home extends Fragment implements LoginListener {
    public View rootView;
    public ImageView HomeBg;
    public ImageView buttonLoginLogout;
    public TextView chi;
    public TextView eng;
    public ColorStateList oldColor;
    public SharedPreferences prefs;
    public EasyTracker tracker = null;

    //Facebook login
    private Session.StatusCallback statusCallback = new SessionStatusCallback();

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

        tracker = EasyTracker.getInstance(getActivity());
        prefs =  getActivity().getSharedPreferences("memberData", 0);

        getActivity().getActionBar().hide();

        rootView = inflater.inflate(R.layout.home, container, false);
        buttonLoginLogout = (ImageView) rootView.findViewById(R.id.home_connectFB);
        eng = (TextView) rootView.findViewById(R.id.btn_eng);
        chi = (TextView) rootView.findViewById(R.id.btn_chi);

        if (Utility.getLocale(getActivity()).equals("TC")) {
            chi.setTextColor(getActivity().getResources().getColor(
                    android.R.color.white));
            oldColor = eng.getTextColors();
        } else {
            eng.setTextColor(getActivity().getResources().getColor(
                    android.R.color.white));
            oldColor = chi.getTextColors();

        }

        eng.setOnClickListener(setChangeLangListener("EN"));
        chi.setOnClickListener(setChangeLangListener("TC"));

        //Facebook login
        Settings.addLoggingBehavior(LoggingBehavior.INCLUDE_ACCESS_TOKENS);

        Session session = Session.getActiveSession();
        if (session == null) {
            if (savedInstanceState != null) {
                session = Session.restoreSession(getActivity(), null, statusCallback, savedInstanceState);
            }
            if (session == null) {
                session = new Session(getActivity());
            }
            Session.setActiveSession(session);
            if (session.getState().equals(SessionState.CREATED_TOKEN_LOADED)) {
                session.openForRead(new Session.OpenRequest(this).setCallback(statusCallback));
            }
        }

       updateView();

        return rootView;
    }

    @Override
    public void onStart() {
        super.onStart();
        Session.getActiveSession().addCallback(statusCallback);
        tracker.set(Fields.SCREEN_NAME, "Landing Page " + Utility.getLocale(getActivity()));
        tracker.send(MapBuilder.createAppView().build());
    }

    @Override
    public void onStop() {
        super.onStop();
        Session.getActiveSession().removeCallback(statusCallback);
        EasyTracker.getInstance(getActivity()).activityStop(getActivity());
    }

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

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        Session session = Session.getActiveSession();
        Session.saveSession(session, outState);
    }

    private void updateView() {
        Session session = Session.getActiveSession();
        if (session.isOpened()) {
            // get request

            if (!session.getAccessToken().equals(prefs.getString("token", "")))
                new FormSubmit(getActivity(),this,tracker).execute("login", session.getAccessToken());
            else
                onTaskComplete(prefs.getString("token", ""),prefs.getString("memberId", ""));

        } else {
            buttonLoginLogout.setImageResource(R.drawable.landing_btn_connect_facebook);
            buttonLoginLogout.setOnClickListener(new View.OnClickListener() {
                public void onClick(View view) { onClickLogin(); }
            });
        }
    }

    private void onClickLogin() {
        Session session = Session.getActiveSession();
        if (!session.isOpened() && !session.isClosed()) {
            session.openForRead(new Session.OpenRequest(this).setCallback(statusCallback));
        } else {
            Session.openActiveSession(getActivity(), this, true, statusCallback);
        }
    }

    private class SessionStatusCallback implements Session.StatusCallback {
        @Override
        public void call(Session session, SessionState state, Exception exception) {
            updateView();
        }
    }

    public OnClickListener setChangeLangListener(final String lang) {
        OnClickListener changeLangListener = new OnClickListener() {
            @Override
            public void onClick(View arg0) {
                Configuration config = new Configuration(getResources().getConfiguration());

                if (Utility.getLocale(getActivity()).equals("TC") && lang.equals("EN")) {
                    tracker.send(MapBuilder.createEvent("menu_click","language", "switchEN", null).build());
                    config.locale = Locale.ENGLISH;
                    chi.setTextColor(oldColor);
                    eng.setTextColor(getActivity().getResources().getColor(
                            android.R.color.white));
                } else if (Utility.getLocale(getActivity()).equals("EN") && lang.equals("TC")) {
                    tracker.send(MapBuilder.createEvent("menu_click","language", "switchTC", null).build());
                    config.locale = Locale.TRADITIONAL_CHINESE;
                    eng.setTextColor(oldColor);
                    chi.setTextColor(getActivity().getResources().getColor(
                            android.R.color.white));
                }

                getResources().updateConfiguration(config,getResources().getDisplayMetrics());

                onConfigurationChanged(config);
            }
        };
        return changeLangListener;
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
      super.onConfigurationChanged(newConfig);
      Intent intent = getActivity().getIntent();
      intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
      getActivity().finish();
      startActivity(intent);
    }

    @Override
    public void onResume() {
        super.onResume();
        AppEventsLogger.activateApp(getActivity(),getResources().getString(R.string.app_id));
    }

    @Override
    public void onTaskComplete(String token, String memberId) {
        Toast.makeText(getActivity(), "t:" + token + "m:" + memberId, Toast.LENGTH_LONG).show();

        buttonLoginLogout.setImageResource(R.drawable.landing_btn_take_a_selfie);
        buttonLoginLogout.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) { 
                ((LandingPage)getActivity()).tabHost.setCurrentTab(2);
            }
        });
    }

    @Override
    public void onTaskFailure(String errorMsg) {
        Toast.makeText(getActivity(), errorMsg, Toast.LENGTH_LONG).show();
    }

    public void saveMemberInfo(String token, String memberId){
        SharedPreferences.Editor editor = prefs.edit();
        editor.putString("token", token);
        editor.putString("memberId", memberId);
        editor.commit();
    }

}

Answer 1

如下所示更新您的 SessionStatusCallback() 方法并检查输出。

如果有效，则将其标记为已接受的答案。

private class SessionStatusCallback implements Session.StatusCallback {
    @Override
    public void call(Session session, SessionState state, Exception exception) {
        if (session.isOpened()) {
            updateView();
        }
    }
}

SessionStatusCallback() 方法将在您的 session 从一种状态更改为另一种状态时每次调用。

在登录 Facebook 之前，您的 SessionState 是 SessionState.CLOSED。当您尝试登录 Facebook 并且身份验证步骤成功时，您的 session 将变为 SessionState.OPENING，此时您的 SessionStatusCallback() 方法将被执行。

但在当前情况下，您的 session 尚未完全打开，它正在打开过程中。因此，在此之后，当您的 session 完全打开时， session 状态更改为 SessionState.OPENED，因此再次调用您的 SessionStatusCallback() 方法。

这就是为什么按照我上面的描述更改您的 SessionStatusCallback() 方法并且它将完美运行的原因。