我正在尝试将facebook登录与我的应用程序集成。这很简单：用户点击我登录屏幕上的一个按钮，我从facebook上获得他们的电子邮件和其他信息，然后我将这些信息提交到我的网站，并让他们成为一个帐户（我不使用密码，所以这很管用）。
然而，登录按钮只工作了1/3的时间。其他时候，它启动facebook活动时，我会在facebook屏幕上看到一个加载微调器，然后应用程序退出到我的主屏幕。没有强制关闭通知，没有logcat错误，什么都没有。
以下是我的登录活动代码（与facebook相关的部分）：

package com.taptag.beta;
/**IMPORTS REMOVED FOR BREVITY**/
public class FacebookLogInActivity extends NetworkActivity {
    public static final String APP_ID = "OMITTED FOR PRIVACY";
    public static final String LOG_OUT = "Log Out";
    Facebook facebook = new Facebook(APP_ID);
    private AsyncFacebookRunner mAsyncRunner;
    private Handler mHandler;
    private SharedPreferences mPrefs;
    private Button mLoginButton;
    private static final String[] PERMISSIONS = { "email" };
    private EditText firstName;
    private EditText lastName;
    private EditText email;
    private Button signupButton;
    private TextView errorView;
    private ProgressBar facebookSpinner;
    private ProgressBar signupSpinner;
    //Taken from mkyong
    private static final String EMAIL_PATTERN = "^[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";
    private Pattern emailPattern;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.facebook_main);
        mPrefs = getSharedPreferences("TapTag", MODE_PRIVATE);
        Integer userId = mPrefs.getInt("user_id", -1);
        mLoginButton = (Button) findViewById(R.id.loginButton);
        // Facebook properties
        mAsyncRunner = new AsyncFacebookRunner(facebook);
        mHandler = new Handler();
        // Get existing saved session information
        String access_token = mPrefs.getString("access_token", null);
        long expires = mPrefs.getLong("access_expires", 0);
        if (access_token != null) {
            facebook.setAccessToken(access_token);
        }
        if (expires != 0) {
            facebook.setAccessExpires(expires);
        }
        errorView = (TextView) findViewById(R.id.signupError);
        facebookSpinner = (ProgressBar) findViewById(R.id.facebookSpinner);
        signupSpinner = (ProgressBar) findViewById(R.id.signupSpinner);
        hideSpinners();
        errorView.setVisibility(View.GONE);
        emailPattern = Pattern.compile(EMAIL_PATTERN);
        firstName = (EditText) findViewById(R.id.signupFirstName);
        lastName = (EditText) findViewById(R.id.signupLastName);
        email = (EditText) findViewById(R.id.signupEmail);
        signupButton = (Button) findViewById(R.id.signupButton);
        signupButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                boolean isValid = validateInputs();
                if (isValid) {
                    SignupTask signupTask = new SignupTask();
                    signupTask.execute(null, null);
                }
            }
        });
        mLoginButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                if (!facebook.isSessionValid()) {
                    logIn();
                } else {
                    logOut();
                }
            }
        });
    }
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        facebook.authorizeCallback(requestCode, resultCode, data);
    }
    @Override
    public void onResume() {
        super.onResume();
        // Extend the session information if it is needed
        //if (facebook != null && !facebook.isSessionValid()) {
            facebook.extendAccessTokenIfNeeded(this, null);
        //}
        if (LOG_OUT.equals(getIntent().getAction())) {
            logOut();
        } else  {
            Integer userId = mPrefs.getInt("user_id", -1);
            if (userId > 0) {
                continueToHomeScreen();
            }
        }
    }
    @Override
    public void onBackPressed() {
        //Do nothing, don't want people getting back into the app
    }
    /**
     * Validate the signup form.  True if valid, false otherwise.
     * @return
     */
    public boolean validateInputs() {
        /**NOT RELEVANT**/
    }
    private FacebookUserInfo userFromForm() {
        /**NOT RELEVANT**/
    }
    private boolean validateFirstName() {
        /**NOT RELEVANT**/
    }
    private boolean validateLastName() {
        /**NOT RELEVANT**/
    }
    private boolean validateEmail() {
        /**NOT RELEVANT**/
    }
    public void hideSpinners() {
        facebookSpinner.setVisibility(View.GONE);
        signupSpinner.setVisibility(View.GONE);
    }
    public void continueToHomeScreen() {
        Intent toHomeScreen = new Intent(FacebookLogInActivity.this, HomeScreenActivity.class);
        FacebookLogInActivity.this.startActivity(toHomeScreen);
    }
    public void logIn() {
        facebookSpinner.setVisibility(View.VISIBLE);
        mLoginButton.setVisibility(View.GONE);
        facebook.authorize(FacebookLogInActivity.this, PERMISSIONS, new DialogListener() {
            @Override
            public void onComplete(Bundle values) {
                SharedPreferences.Editor editor = mPrefs.edit();
                editor.putString("access_token", facebook.getAccessToken());
                editor.putLong("access_expires", facebook.getAccessExpires());
                editor.commit();
                requestUserData();
            }
            @Override
            public void onFacebookError(FacebookError e) {
                mLoginButton.setVisibility(View.VISIBLE);
                hideSpinners();
            }
            @Override
            public void onError(DialogError e) {
                mLoginButton.setVisibility(View.VISIBLE);
                hideSpinners();
            }
            @Override
            public void onCancel() {
                mLoginButton.setVisibility(View.VISIBLE);
                hideSpinners();
            }
        });
    }
    public void logOut() {
        /**NOT RELEVANT**/
    }
    public void requestUserData() {
        Bundle params = new Bundle();
        params.putString("field name", "name");
        params.putString("field email", "email");
        mAsyncRunner.request("me", params, new BaseRequestListener() {
            @Override
            public void onComplete(final String response, final Object state) {
                FacebookUserInfo facebookUserInfo = TapTagAPI.userInfoFromFacebook(response);
                UserFetchResponse userFetchResponse = TapTagAPI.fetchUser(facebookUserInfo);
                if (!userFetchResponse.hasError()) {
                    commitUserInfo(userFetchResponse);
                    continueToHomeScreen();
                } else {
                    mHandler.post(new Runnable() {
                        @Override
                        public void run() {
                            hideSpinners();
                            mLoginButton.setVisibility(View.VISIBLE);
                        }
                    });
                }
            }
        });
    }
    public void commitUserInfo(UserFetchResponse userFetchResponse) {
        SharedPreferences.Editor editor = mPrefs.edit();
        editor.putInt("user_id", userFetchResponse.getId());
        editor.putString("user_name", userFetchResponse.getFirst() + " " + userFetchResponse.getLast());
        editor.commit();
    }
    public class SignupTask extends AsyncTask<Void, Void, UserFetchResponse> {
        @Override
        protected void onPreExecute() {
            signupSpinner.setVisibility(View.VISIBLE);
            signupButton.setVisibility(View.GONE);
        }
        @Override
        protected UserFetchResponse doInBackground(Void... arg0) {
            FacebookUserInfo user = userFromForm();
            UserFetchResponse response = TapTagAPI.fetchUser(user);
            return response;
        }
        @Override
        protected void onPostExecute(UserFetchResponse response) {
            if (response.success()) {
                commitUserInfo(response);
                continueToHomeScreen();
            } else {
                errorView.setVisibility(View.VISIBLE);
            }
        }
    }
}