RecyclerView + Adapter ist nicht sichtbar nach dem ersten Mal auf Fragment

Question

Ich habe ein Fragment und dies enthält eine RecyclerView und das ist mit Retrofit 2 bevölkern, in meinem Listener bevölkern den Adapter und auf dem RecyclerView setzen.

Wenn die App getötet wird und neu starten, das erste Mal, wenn ich dieses Fragment öffnen wird korrekt angezeigt, aber wenn ich drücken Sie die Taste oder wenn das Fragment ändern, wenn ich versuche, in das gleiche Fragment der RecyclerView mit Der Adapter wird niemals angezeigt.

Ich verwende diese auf gradle:

compile 'com.android.support:cardview-v7:25.0.1' 
compile 'com.android.support:recyclerview-v7:25.0.1' 
compile 'com.android.support:support-v4:25.0.1' 

das ist mein XML:

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:app="http://schemas.android.com/apk/res-auto" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:background="@android:color/white" 
android:orientation="vertical"> 

<include 
    android:id="@+id/my_toolbar" 
    layout="@layout/standard_toolbar" /> 

<com.sample.ui.CustomSwipeRefreshLayout 
    android:id="@+id/ptr_layout" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:visibility="visible"> 

    <LinearLayout 
     android:layout_width="match_parent" 
     android:layout_height="match_parent"> 

     <include 
      android:id="@+id/empty_rewards" 
      layout="@layout/no_near_by_rewards" 
      android:visibility="gone"/> 

     <android.support.v7.widget.RecyclerView 
      android:id="@+id/rewards_list" 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:scrollbars="vertical"/> 

    </LinearLayout> 

</com.sample.ui.CustomSwipeRefreshLayoutt> 
</LinearLayout> 

dies mein Fragment Klasse ist:

public class RewardsListFragment extends BaseFragment implements GoogleApiClient.ConnectionCallbacks, 
    GoogleApiClient.OnConnectionFailedListener, LocationListener { 

public static volatile boolean refreshOffersListFragment = false; 
public static boolean comingFromDetailFragment = false; 
private static GoogleApiClient locationClient; 

private int LIMIT = 7; 

private View noRewards; 

ArrayList<MerchantListItem> nMerchantList = new ArrayList<>(); 

private RewardsRVArrayAdapter mAdapter; 
private RecyclerView rList; 

// Bool to track whether the app is already resolving an error 
private boolean resolvingError = false; 
private boolean awaitingPermission = false; 
private boolean appSettingsSelected = false; 
private boolean locationSettingsSelected = false; 
private boolean gpsOffScreenDisplayed = false; 
private boolean awaitingHomeCoordinates = true; 

private double homeLatitude = 0.0; 
private double homeLongitude = 0.0; 
private Location currentLocation = null; 
private String permissionStatus; 

MerchantListRequest listRequest; 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
    return inflater.inflate(R.layout.rewards_list_fragment_2, container, false); 
} 

@Override 
public void onViewCreated(View view, Bundle savedInstanceState) { 
    super.onViewCreated(view, savedInstanceState); 

    rList = (RecyclerView) view.findViewById(rewards_list); 
    noRewards = view.findViewById(R.id.empty_rewards); 

    rList.setHasFixedSize(true); 
    LinearLayoutManager layoutManager = new LinearLayoutManager(getContext()); 
    layoutManager.setOrientation(LinearLayoutManager.VERTICAL); 
    rList.setLayoutManager(layoutManager); 
} 

@Override 
public void onDetach() { 
    super.onDetach(); 
    if(mAdapter != null) 
    { 
     mAdapter = null; 
    } 

    if(rList.getAdapter() != null) 
    { 
     rList.setAdapter(null); 
    } 

    if(listRequest != null) { 
     listRequest.getCall().cancel(); 
    } 
} 

@Override 
public void onActivityCreated(Bundle savedInstanceState) { 
    super.onActivityCreated(savedInstanceState); 

    homeLatitude = ChimeApplication.user.latitude; 
    homeLongitude = ChimeApplication.user.longitude; 

    startIndeterminateProgress(); 
    currentLocation = new Location(""); 
    currentLocation.setLatitude(homeLatitude); 
    currentLocation.setLongitude(homeLongitude); 
    awaitingHomeCoordinates = false; 

    mAdapter = new RewardsRVArrayAdapter(new ArrayList<MerchantListItem>()); 
    rList.setAdapter(mAdapter); 

} 

@Override 
public void onResume() { 
    super.onResume(); 
    getRewards(); 
} 

private void refreshOffers() { 
     startIndeterminateProgress(); 
     final int first_row = 0; 
     final int num_rows = LIMIT; 
     listRequest = new MerchantListRequest(parentActivity, currentLocation.getLatitude(), currentLocation.getLongitude(), first_row, num_rows); 
     listRequest.execute(new MerchantListRequestListener(getContext())); 
} 

@Override 
public void onRefresh() { 
    refreshOffersListFragment = true; 
    refreshOffers(); 
} 

@Override 
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { 
    inflater.inflate(R.menu.offers_list_menu, menu); 
} 


@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    if (item.getItemId() == R.id.refresh) { 
     refreshOffersListFragment = true; 
     refreshOffers(); 
     return true; 
    } 

    return false; 
} 

@Override 
public void onPause() { 
    super.onPause(); 

    if (locationClient != null && locationClient.isConnected()) { 
     locationClient.disconnect(); 
    } 
} 

private void showList() { 
    noRewards.setVisibility(View.GONE); 
    rList.setVisibility(View.VISIBLE); 
} 

private void hideList() { 
    noRewards.setVisibility(View.VISIBLE); 
    rList.setVisibility(View.GONE); 
} 

private void setMerchantsList(ArrayList<MerchantListItem> results) { 

    if (nMerchantList != null && nMerchantList.size() > 0) { 
     nMerchantList.clear(); 
    } 

    for (MerchantListItem item : results) { 
     nMerchantList.add(item); 
    } 

    if (mAdapter == null) { 
     mAdapter = new RewardsRVArrayAdapter(nMerchantList); 
     rList.setAdapter(null); 
     rList.setAdapter(mAdapter); 
    } else { 
     mAdapter.addAll(nMerchantList); 
     rList.postInvalidate(); 
    } 
} 

private class MerchantListRequestListener extends BaseRetrofitRequestListener<MerchantListResult> { 

    public MerchantListRequestListener(Context context) { 
     super(context); 
    } 

    @Override 
    public void onRequestFailed(int code, String errorMessage) { 
     android.util.Log.e("RECYCLERVIEW", "FAIL request"); 
     stopIndeterminateProgress(); 
     dialogCheck(); 
     if (errorMessage != null && !errorMessage.isEmpty() && isVisible()) { 
      Toast.makeText(context, errorMessage, Toast.LENGTH_LONG).show(); 
      hideList(); 
     } 
    } 

    @Override 
    public void onRequestSuccessful(Response<MerchantListResult> response) { 
     dialogCheck(); 
     stopIndeterminateProgress(); 
     if (response != null && response.body().results != null) { 
      showList(); 

      setMerchantsList(response.body().results); 


     } else { 
      hideList(); 
     } 
    } 

    private void dialogCheck() { 
     if (!Utils.isHighAccuracySet(parentActivity) && ContextCompat.checkSelfPermission(parentActivity, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED && 
       ContextCompat.checkSelfPermission(parentActivity, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) { 
      displayGPSOffDialog(); 
     } 
    } 
} 

private void getRewards() { 
    if (ContextCompat.checkSelfPermission(parentActivity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) { 
     if (!(RewardsListFragment.this).shouldShowRequestPermissionRationale(Manifest.permission.ACCESS_FINE_LOCATION)) { 
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { 
       awaitingPermission = true; 
       (RewardsListFragment.this).requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION, 
           Manifest.permission.ACCESS_COARSE_LOCATION}, 
         PermConst.REWARDS_LOCATION_PERMISSION_REQUESTED); 
      } 
     } else { 
      displayPermissionDeniedDialog(); 
      final int first_row = 0; 
      final int num_rows = LIMIT; 

      listRequest = new MerchantListRequest(parentActivity, currentLocation.getLatitude(), currentLocation.getLongitude(), first_row, num_rows); 
      listRequest.execute(new MerchantListRequestListener(parentActivity)); 
      awaitingPermission = false; 
     } 

    } else { 
     if (locationClient != null && !locationClient.isConnected() && Utils.isHighAccuracySet(parentActivity)) { 
      // Turn off no offers and gps disabled screens only if the no offers screen is not currently displayed. 
      locationClient.connect(); 
     } else { 
      if (locationClient == null && Utils.isHighAccuracySet(parentActivity)) { 
       refreshOffersListFragment = true; 
       locationClient = new GoogleApiClient.Builder(parentActivity.getApplicationContext()) 
         .addConnectionCallbacks(this).addOnConnectionFailedListener(this).addApi(LocationServices.API).build(); 
       locationClient.connect(); 
      } else { 
       final int first_row = 0; 
       final int num_rows = LIMIT; 

       listRequest = new MerchantListRequest(parentActivity, currentLocation.getLatitude(), currentLocation.getLongitude(), first_row, num_rows); 
       listRequest.execute(new MerchantListRequestListener(parentActivity)); 
       if (!Utils.isHighAccuracySet(parentActivity)) { 
        gpsOffScreenDisplayed = true; 
       } 
      } 
     } 
     awaitingPermission = false; 
    } 

    mPullToRefreshLayout.setEnabled(true); 

} 

Und schließlich das ist mein Adapter :

public class RewardsRVArrayAdapter extends RecyclerView.Adapter<RewardsRVArrayAdapter.ViewHolder> { 

private List<MerchantListItem> results; 
private final int sdkVersion; 
private Bitmap defaultImage; 
private final DecimalFormat dollarFormatter = new DecimalFormat("$##.##"); 

private int lastAnimatedPosition = -1; 

public RewardsRVArrayAdapter(List<MerchantListItem> results) { 
    this.results = results; 
    sdkVersion = Utils.getSDKVersion(); 
    setHasStableIds(false); 
} 

@Override 
public RewardsRVArrayAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
    // create a new view 
    defaultImage = BitmapFactory.decodeResource(parent.getContext().getResources(), R.drawable.big_text); 
    View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.rewards_list_item, parent, false); 
    // set the view's size, margins, paddings and layout parameters 
    return new ViewHolder(v); 
} 

@Override 
public void onViewAttachedToWindow(ViewHolder holder) { 
    super.onViewAttachedToWindow(holder); 
} 

@Override 
public void onViewDetachedFromWindow(ViewHolder holder) { 
    super.onViewDetachedFromWindow(holder); 
} 

@Override 
public void onBindViewHolder(ViewHolder holder, int position) { 
    MerchantListItem offerItem = results.get(position); 
    Deal deal = offerItem.deal != null ? offerItem.deal : null; 

    if (offerItem.type.equalsIgnoreCase(Const.MERCHANT_MERCHANT_STRING)) { 
     setMerchant(holder, offerItem, deal); 
    } else if (offerItem.type.equalsIgnoreCase(Const.MERCHANT_REWARD_STRING)) { 

     setCategoryReward(holder, deal); 
    } 

    //Set up the banner 
    if (offerItem.banner != null && offerItem.banner.text != null && !offerItem.banner.text.isEmpty()) { 
     holder.banner.setVisibility(View.VISIBLE); 
     holder.banner.setText(offerItem.banner.text); 

     //Set color of banner based on type 
     if (offerItem.banner.type.equalsIgnoreCase(Banner.TYPE_FEATURED)) { 
      holder.banner.setBackgroundResource(R.drawable.yellow_banner); 
      holder.banner.setTextColorRes(R.color.text); 
     } else if (offerItem.banner.type.equalsIgnoreCase(Banner.TYPE_PERSONALIZED)) { 
      holder.banner.setBackgroundResource(R.drawable.blue_banner); 
      holder.banner.setTextColorRes(android.R.color.white); 
     } else if (offerItem.banner.type.equalsIgnoreCase(Banner.TYPE_LIMITED)) { 
      holder.banner.setBackgroundResource(R.drawable.orange_banner); 
      holder.banner.setTextColorRes(android.R.color.white); 
     } 

     //For some reason padding did not work in XML so I moved it here 
     holder.banner.setPadding(Utils.convertDpToPixel(10, holder.banner.getContext()), Utils.convertDpToPixel(3, holder.banner.getContext()), 
       Utils.convertDpToPixel(10, holder.banner.getContext()), Utils.convertDpToPixel(3, holder.banner.getContext())); 
    } else { 
     holder.banner.setVisibility(View.GONE); 
    } 
} 

@Override 
public int getItemCount() { 
    return results != null ? results.size() : 0; 
} 

public MerchantListItem getItemAtPosition(int position) 
{ 
    return results.get(position); 
} 

public void addAll(ArrayList<MerchantListItem> newResults) 
{ 
    this.results.clear(); 
    for(MerchantListItem item : newResults) 
    { 
     this.results.add(item); 
    } 
    dataSetChanged(); 
} 

@UiThread 
protected void dataSetChanged() { 
    notifyDataSetChanged(); 
} 

private void setMerchant(final ViewHolder viewHolder, final MerchantListItem offerItem, final Deal deal) { 
    loadCardImage(offerItem.image_url, viewHolder); 
    viewHolder.merchant_name_txt.setText(offerItem.name); 

    if (deal != null) { 
     viewHolder.merchant_offer_txt.setText(deal.name); 
     viewHolder.offer_amount.setText(dollarFormatter.format(deal.promotional_value)); 
    } 
} 

private void setCategoryReward(final ViewHolder viewHolder, Deal deal) { 
    if(deal != null) 
    { 
     loadCardImage(deal.category_reward.card_image_url, viewHolder); 
     viewHolder.merchant_name_txt.setText(deal.category_reward.card_title); 
     viewHolder.merchant_offer_txt.setText(deal.name); 
     viewHolder.offer_amount.setText(dollarFormatter.format(deal.promotional_value)); 
    } 
} 

private void loadCardImage(String url, final ViewHolder viewHolder) { 
    if (url != null && !url.isEmpty()) { 
     Picasso.with(viewHolder.main_layout.getContext()).load(url).memoryPolicy(MemoryPolicy.NO_CACHE, MemoryPolicy.NO_STORE).fit().networkPolicy(NetworkPolicy.NO_CACHE, NetworkPolicy.NO_STORE, NetworkPolicy.OFFLINE).into(viewHolder.main_layout); 
    } else { 
     setDefaultImage(viewHolder.main_layout); 
    } 

} 

@SuppressWarnings("deprecation") 
@SuppressLint("NewApi") 
private void setBackgroundImage(View view, Drawable drawable) { 
    //FIXME we can remove this because we don't support any below to API 16 (JELLY BEAN) 
    if (sdkVersion < android.os.Build.VERSION_CODES.JELLY_BEAN) { 
     view.setBackgroundDrawable(drawable); 
    } else { 
     view.setBackground(drawable); 
    } 
} 

public static class ViewHolder extends RecyclerView.ViewHolder { 
    // each data item is just a string in this case 
    ButtonTextView banner; 
    ButtonTextView merchant_name_txt; 
    HeaderTextView merchant_offer_txt; 
    ImageView main_layout; 
    ButtonTextView offer_amount; 
    public ViewHolder(View v) { 
     super(v); 
     banner = (ButtonTextView) v.findViewById(R.id.banner); 
     merchant_name_txt = (ButtonTextView) v.findViewById(R.id.merchant_name_txt); 
     merchant_offer_txt = (HeaderTextView) v.findViewById(R.id.merchant_reward_txt); 
     main_layout = (ImageView) v.findViewById(R.id.image_layout); 
     offer_amount = (ButtonTextView) v.findViewById(R.id.reward_amount); 
    } 
} 

}

das Seltsame ist, dies geschah auf Android M und N, aber jetzt geschieht auf Android L, war ich über einige Probleme mit RecyclerView zuvor mit Support-Bibliothek zu lesen aber ich kann‘ Ich finde die Lösung.

befestigt ein gif für die Prüfung, was das Verhalten der Gif bug RecyclerView

Answer 1

In folgendem Code in onCreateView in RewardsListFragment

mAdapter = new RewardsRVArrayAdapter(new ArrayList<MerchantListItem>()); 
rList.setAdapter(mAdapter); 

Answer 2

Da ich es nicht direkt überprüfen kann, weil Ihr Projekt viele Abhängigkeiten hat, i vorschlagen, dass Sie jeden Teil Ihrer Methoden protokollieren.

Ich vermute, es gibt einige Fehler auf Ihrer getRewards() Methode. Wenn Ihr Refresh Methode funktioniert gut, können Sie

private boolean firstTime = true; 

@Override 
public void onResume() { 
    super.onResume(); 
    if(firstTime){ 
     getRewards(); 
     firstTime = false;  
    } 
    else{ 
     onRefresh(); 
    } 
} 

statt

verwenden