成功登录Facebook后如何启动新活动？

Question

我正在进行Facebook登录。 在我的主要XML中，我只有Facebook登录按钮。

我想在Facebook成功登录后开始新页面，但是在Facebook成功登录后，它不显示我的新XML页面（欢迎使用XML布局）。 而是显示空白页面。

我怎样才能解决这个问题？

GitHub链接

我的片段：

    public static class PlaceholderFragment extends Fragment {

        private CallbackManager callbackManager;
        private FacebookCallback<LoginResult>callback=new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {

                //Is there problem here?
                AccessToken accessToken=loginResult.getAccessToken();
                Profile profile=Profile.getCurrentProfile();
                Intent intent = new Intent(getActivity().getApplicationContext(), com.berkkarabacak.scarce.Profile.class);
                startActivity(intent);
                //Is there problem here?


            }

            @Override
            public void onCancel() {

            }

            @Override
            public void onError(FacebookException e) {
            }
        };


        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            FacebookSdk.sdkInitialize(getActivity().getApplicationContext());
            callbackManager=CallbackManager.Factory.create();

        }

        @Override


        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            LoginButton loginButton=(LoginButton) rootView.findViewById(R.id.login_button);
            loginButton.setReadPermissions("user_friends");
            loginButton.setFragment(this);
            loginButton.registerCallback(callbackManager,callback);
            return rootView;
            }

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

Answer 1

使用活动上下文

 Intent intent = new Intent(getActivity(), com.berkkarabacak.scarce.Profile.class);

Answer 2

请尝试这个；

        Fragment fragment = new sendFragment();
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        fragmentTransaction.replace(R.id.content, fragment);
        fragmentTransaction.commit();