我已经查看过有关此问题的其他问题，但我仍然不确定如何实施OnFragmentInteractionListener。我正在进行facebook登录，我想在我的主要活动中实现OnFragmentInteractionListener，但我不知道如何（它抛出与onStop()发生冲突的错误，并且还希望被声明为抽象） 。我需要帮助
这是MainActivity
package com.eren.valour;
import android.app.ActionBar;
import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.Menu;
import android.view.MenuItem;
import android.content.Intent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.Toast;
import com.facebook.Session;
import com.facebook.SessionState;
import com.facebook.UiLifecycleHelper;
import static com.eren.valour.R.id.*;
public class MainScreen extends ActionBarActivity implements FacebookLoginDialogueFragment.OnFragmentInteractionListener {
private static final int FBSPLASH = 0;
private static final int FBSELECTION = 1;
private static final int FBFRAGMENT_COUNT = FBSELECTION + 1;
private Fragment[] fragments = new Fragment[FBFRAGMENT_COUNT];
ImageButton fblogin;
Session session = Session.getActiveSession();
private boolean isResumed = false;
private UiLifecycleHelper uiHelper;
private Session.StatusCallback callback =
new Session.StatusCallback() {
@Override
public void call(Session session,
SessionState state, Exception exception) {
onSessionStateChange(session, state, exception);
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().setDisplayShowCustomEnabled(true);
setTitle("Valour");
setContentView(R.layout.activity_main_screen);
uiHelper = new UiLifecycleHelper(this, callback);
uiHelper.onCreate(savedInstanceState);
FragmentManager fm = getSupportFragmentManager();
fragments[FBSPLASH] = fm.findFragmentById(R.id.splashFragment);
fragments[FBSELECTION] = fm.findFragmentById(R.id.selectionFragment);
FragmentTransaction transaction = fm.beginTransaction();
for (int i = 0; i < fragments.length; i++) {
transaction.hide(fragments[i]);
}
transaction.commit();
getScreenRes();
}
public void getScreenRes() {
DisplayMetrics display = this.getResources().getDisplayMetrics();
int screenwidth = display.widthPixels;
double buttonheight = screenwidth / 2.66666667;
int screenheight = (int) Math.round(buttonheight);
// ImageButton serviceList = (ImageButton) findViewById(R.id.addservice);
// ViewGroup.LayoutParams servicelist = serviceList.getLayoutParams();
// servicelist.width = screenwidth;
// servicelist.height = screenheight;
//Get screen dimensions and define button variables
ImageButton redditLogin = (ImageButton) findViewById(R.id.redditLogin);
ViewGroup.LayoutParams reddit = redditLogin.getLayoutParams();
reddit.width = screenwidth;
reddit.height = screenheight;
ImageButton fbLogin = (ImageButton) findViewById(R.id.facebookLogin);
ViewGroup.LayoutParams fb = fbLogin.getLayoutParams();
fb.width = screenwidth;
fb.height = screenheight;
ImageButton instaLogin = (ImageButton) findViewById(R.id.instagramLogin);
ViewGroup.LayoutParams insta = instaLogin.getLayoutParams();
insta.width = screenwidth;
insta.height = screenheight;
ImageButton twitLogin = (ImageButton) findViewById(R.id.twitterLogin);
ViewGroup.LayoutParams twit = twitLogin.getLayoutParams();
twit.width = screenwidth;
twit.height = screenheight;
// set button size
instaLogin.setLayoutParams(insta);
fbLogin.setLayoutParams(fb);
twitLogin.setLayoutParams(twit);
redditLogin.setLayoutParams(reddit);
}
public void facebookLogin(View v) {
if (session == null) {
session = new Session(getApplicationContext());
}
Session.setActiveSession(session);
}
public void instagramLogin(View v) {
serviceIncomplete();
}
public void redditLogin(View v) {
serviceIncomplete();
}
public void twitterLogin(View v) {
serviceIncomplete();
}
private void showFragment(int fragmentIndex, boolean addToBackStack) {
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction transaction = fm.beginTransaction();
for (int i = 0; i < fragments.length; i++) {
if (i == fragmentIndex) {
transaction.show(fragments[i]);
} else {
transaction.hide(fragments[i]);
}
}
if (addToBackStack) {
transaction.addToBackStack(null);
}
transaction.commit();
}
private void onSessionStateChange(Session session, SessionState state, Exception exception) {
// Only make changes if the activity is visible
if (isResumed) {
FragmentManager manager = getSupportFragmentManager();
// Get the number of entries in the back stack
int backStackSize = manager.getBackStackEntryCount();
// Clear the back stack
for (int i = 0; i < backStackSize; i++) {
manager.popBackStack();
}
if (state.isOpened()) {
// If the session state is open:
// Show the authenticated fragment
showFragment(FBSELECTION, false);
} else if (state.isClosed()) {
// If the session state is closed:
// Show the login fragment
showFragment(FBSPLASH, false);
}
}
}
@Override
protected void onResumeFragments() {
super.onResumeFragments();
Session session = Session.getActiveSession();
if (session != null && session.isOpened()) {
// if the session is already open,
// try to show the selection fragment
showFragment(FBSELECTION, false);
} else {
// otherwise present the splash screen
// and ask the person to login.
showFragment(FBSPLASH, false);
}
}
//show toast if service is not finished.
public void serviceIncomplete() {
Context context = getApplicationContext();
CharSequence text = "Coming Soon!";
int duration = Toast.LENGTH_LONG;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
}
public void firstTime() {
startActivity(new Intent(getApplicationContext(), FirstTimeLogin.class));
}
@Override
public void onResume() {
super.onResume();
uiHelper.onResume();
isResumed = true;
}
@Override
public void onPause() {
super.onPause();
uiHelper.onPause();
isResumed = false;
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
uiHelper.onActivityResult(requestCode, resultCode, data);
}
@Override
public void onDestroy() {
super.onDestroy();
uiHelper.onDestroy();
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
uiHelper.onSaveInstanceState(outState);
}
}
这是Fragment
package com.eren.valour;
import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* A simple {@link Fragment} subclass.
* Activities that contain this fragment must implement the
* {@link FacebookLoginDialogueFragment.OnFragmentInteractionListener} interface
* to handle interaction events.
* Use the {@link FacebookLoginDialogueFragment#newInstance} factory method to
* create an instance of this fragment.
*/
public class FacebookLoginDialogueFragment extends android.support.v4.app.Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public FacebookLoginDialogueFragment() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment FacebookLoginDialogueFragment.
*/
// TODO: Rename and change types and number of parameters
public static FacebookLoginDialogueFragment newInstance(String param1, String param2) {
FacebookLoginDialogueFragment fragment = new FacebookLoginDialogueFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_facebook_login_dialogue,
container, false);
return view;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(Uri uri);
}
}
答案 0 :(得分：0)
您应该在活动中实施onFragmentInteraction
@Override
public void onFragmentInteraction(Uri uri) {
}