我有一个奇怪的情况，我有一个Activity托管TabLayout/Viewpager，根据对Firebase数据库的更改来填充数据。不幸的是，RecyclerView没有填充，我在logcat中收到以下错误。我相信即使片段不在屏幕上也会加载片段，这会导致RecyclerView的填充错误。当我旋转屏幕时，RecyclerView会填充，这也很奇怪：
12-13 21:31:40.013 12490-12490/com.troychuinard.fanpolls E/RecyclerView: No adapter attached; skipping layout
以下是我在主持人ViewPager中的Activity适配器：
public class SectionPagerAdapter extends FragmentPagerAdapter {
public SectionPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new TrendingFragment();
case 1:
return new FollowingFragment();
case 2:
return new LiveFragment();
default:
return new TrendingFragment();
}
}
@Override
public int getCount() {
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return getResources().getString(R.string.trending_text);
case 1:
return getResources().getString(R.string.following_text);
case 2:
return getResources().getString(R.string.new_text);
default:
return getResources().getString(R.string.trending_text);
}
}
}
以下是我在RecyclerView中初始化onCreateView() LiveFragment内部TabLayout功能的完整片段，即public class LiveFragment extends 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";
private RecyclerView mRecyclerview;
private DatabaseReference mBaseRef;
private DatabaseReference mPollsRef;
private LinearLayoutManager mLayoutManager;
private FirebaseRecyclerAdapter <Poll, PollHolder> mFireAdapter;
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public LiveFragment() {
// 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 LiveFragment.
*/
// TODO: Rename and change types and number of parameters
public static LiveFragment newInstance(String param1, String param2) {
LiveFragment fragment = new LiveFragment();
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);
mBaseRef = FirebaseDatabase.getInstance().getReference();
mPollsRef = mBaseRef.child("Polls");
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
final View v = inflater.inflate(R.layout.fragment_new, container, false);
Log.v("TAG", "ON CREATE CALLED FROM NEW");
mLayoutManager = new LinearLayoutManager(getActivity());
mLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
mRecyclerview = (RecyclerView)v.findViewById(R.id.new_RecyclerView);
if (mRecyclerview != null){
mRecyclerview.setHasFixedSize(true);
}
if (mRecyclerview == null){
Log.v("TAG", "RECYCLERVIEW NULL");
} else if (mLayoutManager == null){
Log.v("TAG", "LAYOUTMANAGER NULL");
} else if (mFireAdapter == null) {
Log.v("TAG", "mFIREADAPTER NULL");
}
return v;
}
// 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 onStart() {
super.onStart();
}
@Override
public void onStop() {
super.onStop();
if (mFireAdapter != null){
mFireAdapter.cleanup();
}
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mRecyclerview.setLayoutManager(mLayoutManager);
mFireAdapter = new FirebaseRecyclerAdapter<Poll, PollHolder>(Poll.class, R.layout.latest_item, PollHolder.class, mPollsRef) {
@Override
protected void populateViewHolder(PollHolder viewHolder, Poll model, int position) {
viewHolder.mPollQuestion.setText(model.getQuestion());
Picasso.with(getActivity().getApplicationContext())
.load(model.getImage_URL())
.fit()
.into(viewHolder.mPollImage);
Log.v("QUESTION", model.getQuestion());
Log.v("IMAGE", model.getImage_URL());
}
};
mRecyclerview.setAdapter(mFireAdapter);
mPollsRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot x : dataSnapshot.getChildren()){
mFireAdapter.notifyItemInserted(0);
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public static class PollHolder extends RecyclerView.ViewHolder {
TextView mPollQuestion;
ImageView mPollImage;
public PollHolder(View itemView) {
super(itemView);
mPollQuestion = (TextView) itemView.findViewById(R.id.latest_item_question);
mPollImage = (ImageView) itemView.findViewById(R.id.pollThumbNailImage);
}
}
/**
* 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
void onFragmentInteraction(Uri uri);
}
}
中的标签3：
Braintree_Exception_SSLCertificate答案 0 :(得分：1)
从firebase读取数据后，将适配器从onCreateView移动到onActivityCreated方法。
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
//read Poll data from firebase mPollsRef for example
//.... database reference to firebase
//Query mPollsRef = databaseReference.child("pools").limitToFirst(200);
mRecyclerview.setLayoutManager(mLayoutManager);
mFireAdapter = new FirebaseRecyclerAdapter<Poll, PollHolder>(Poll.class, R.layout.latest_item, PollHolder.class, mPollsRef) {
@Override
protected void populateViewHolder(PollHolder viewHolder, Poll model, int position) {
viewHolder.mPollQuestion.setText(model.getQuestion());
Picasso.with(getActivity().getApplicationContext())
.load(model.getImage_URL())
.fit()
.into(viewHolder.mPollImage);
Log.v("QUESTION", model.getQuestion());
Log.v("IMAGE", model.getImage_URL());
}
};
mRecyclerview.setAdapter(mFireAdapter);
}
我在HostActivity.java初始化寻呼机的代码
private FragmentPagerAdapter mPagerAdapter;
private ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_absence);
// Create the adapter that will return a fragment for each section
mPagerAdapter = new FragmentPagerAdapter(getSupportFragmentManager()) {
private final Fragment[] mFragments = new Fragment[] {
new MyAbsenceFragment(),
new MyAttendanceFragment(),
new AbsTypesFragment(),
new LiveFragment(),
};
private final String[] mFragmentNames = new String[] {
"Absences",
"Attendances",
"AbsTypes",
"Live"
};
@Override
public Fragment getItem(int position) {
return mFragments[position];
}
@Override
public int getCount() {
return mFragments.length;
}
@Override
public CharSequence getPageTitle(int position) {
return mFragmentNames[position];
}
};
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mPagerAdapter);