populateViewHolder không thực thi với FirebaseRecyclerAdapter (Android)

Question

Tôi đang cố gắng sử dụng FirebaseRecyclerAdapter để điền RecyclerView vào một đoạn, với dữ liệu từ cơ sở dữ liệu Firebase của tôi.

Vấn đề chính của tôi là phương pháp populateViewHolder không bao giờ được gọi, vì vậy tôi không hiển thị gì trong số RecyclerView.

Tôi làm theo các bước từ tài liệu Firebase UI:

https://github.com/firebase/FirebaseUI-Android/blob/master/database/README.md

Các quy tắc trên cơ sở dữ liệu căn cứ hỏa lực của tôi:

{ 
    "rules": { 
    ".read": "true", 
    ".write": "true" 
    } 
} 

Trong tôi gradle, tôi đã thêm sự phụ thuộc này :

compile 'com.firebaseui:firebase-ui-database:0.4.1' 

Dưới đây là phương pháp onCreateView trong đoạn tôi:

public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    View rootView = inflater.inflate(R.layout.fragment_dev_list, container, false); 

    Log.d("ROOT_VIEW", rootView.toString()); 

    mRecyclerView = (RecyclerView) rootView.findViewById(R.id.recycler_view); 
    Log.d("RECYCLER_VIEW", mRecyclerView.toString()); 

    mRecyclerView.setHasFixedSize(true); 
    mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity())); 
    Log.d("ITEM_RECYCLER", Integer.toString(mRecyclerView.getLayoutManager().getItemCount())); 

    DatabaseReference devs = FirebaseDatabase.getInstance().getReference().child("users").child("devs"); 

    FirebaseRecyclerAdapter<Developer, DeveloperViewHolder> adapter = 
      new FirebaseRecyclerAdapter<Developer, DeveloperViewHolder>(
        Developer.class, 
        R.layout.dev_list_row, 
        DeveloperViewHolder.class, 
        devs 
      ) { 
       @Override 
       protected void populateViewHolder(DeveloperViewHolder viewHolder, Developer developer, int position) { 
        Log.d("ON CREATE VIEW", "before"); 
        viewHolder.setFirstName(developer.getFirstN()); 
        viewHolder.setLastName(developer.getLastN()); 
        viewHolder.setAddress(developer.getAddress()); 
        Log.d("ON CREATE VIEW", "populate"); 
       } 
      }; 


    Log.d("COUNT_ADAPTER", Integer.toString(adapter.getItemCount())); 
    Log.d("ADAPTER", adapter.toString()); 
    Log.d("RECYCLER VIEW", mRecyclerView.toString()); 
    mRecyclerView.setAdapter(adapter); 
    Log.d("ON CREATE VIEW", "end"); 

    return rootView; 
} 

Và đây là DeveloperViewHolder tôi lớp:

public static class DeveloperViewHolder extends RecyclerView.ViewHolder { 
    TextView firstName; 
    TextView lastName; 
    TextView address; 
    View mView; 


    public DeveloperViewHolder(View v) { 
     super(v); 
     this.mView = v; 
    } 

    public void setFirstName(String firstN) { 
     this.firstName = (TextView) mView.findViewById(R.id.firstname_row); 
     this.firstName.setText(firstN); 
    } 

    public void setLastName(String lastN) { 
     this.lastName = (TextView) mView.findViewById(R.id.lastname_row); 
     this.lastName.setText(lastN); 
    } 

    public void setAddress(String addr) { 
     this.address = (TextView) mView.findViewById(R.id.address_row); 
     this.address.setText(addr); 
    } 
} 

Các Developer lớp (mô hình lớp):

public class Developer { 

    private String firstN; 
    private String lastN; 
    private String email; 
    private String address; 

     public Developer() { 

     } 

    public Developer(String firstN, String lastN, String email, String address)  { 
     this.firstN = firstN; 
     this.lastN = lastN; 
     this.email = email; 
     this.address = address; 
    } 

    public String getFirstN() { 
     return firstN; 
    } 

    public void setFirstN(String firstN) { 
     this.firstN = firstN; 
    } 

    public String getLastN() { 
     return lastN; 
    } 

    public void setLastN(String lastN) { 
     this.lastN = lastN; 
    } 

    public String getEmail() { 
     return email; 
    } 

    public void setEmail(String email) { 
     this.email = email; 
    } 

    public String getAddress() { 
     return address; 
    } 

    public void setAddress(String address) { 
     this.address = address; 
    } 
} 

Và cuối cùng, một số bản ghi:

[ 07-08 09:42:42.773 18621:18668 D/   ] 
                      HostConnection::get() New Host Connection established 0x7f938cdb65c0, tid 18668 
I/OpenGLRenderer: Initialized EGL, version 1.4 
D/OpenGLRenderer: Enabling debug mode 0 
I/TextInputLayout: EditText added is not a TextInputEditText. Please switch to using that class instead. 
I/TextInputLayout: EditText added is not a TextInputEditText. Please switch to using that class instead. 
I/AppCompatViewInflater: app:theme is now deprecated. Please move to using android:theme instead. 
D/ACTION BAR?: android.support.v7.app.ToolbarActionBar@23efcd8a 
D/ROOT_VIEW: android.widget.LinearLayout{27403c65 V.E..... ......I. 0,0-0,0} 
D/RECYCLER_VIEW: android.support.v7.widget.RecyclerView{23dead3a VFED.V.. ......I. 0,0-0,0 #7f0e00e5 app:id/recycler_view} 
D/ITEM_RECYCLER: 0 
I/DynamiteModule: Considering local module com.google.android.gms.firebase_database:2 and remote module com.google.android.gms.firebase_database:2 
I/DynamiteModule: Selected remote version of com.google.android.gms.firebase_database, version >= 2 
D/COUNT_ADAPTER: 0 
D/ADAPTER: raphaelgrau.example.com.tabsapp.fragment.tabs.DevListFragment$1@29ec2dc7 
D/RECYCLER VIEW: android.support.v7.widget.RecyclerView{23dead3a VFED.V.. ......I. 0,0-0,0 #7f0e00e5 app:id/recycler_view} 
D/ON CREATE VIEW: end 
E/DynamiteModule: Failed to load module descriptor class: Didn't find class "com.google.android.gms.dynamite.descriptors.com.google.firebase.auth.ModuleDescriptor" on path: DexPathList[[zip file "/data/app/raphaelgrau.example.com.tabsapp-1/base.apk"],nativeLibraryDirectories=[/vendor/lib64, /system/lib64]] 
background_crash  E/DynamiteModule: Failed to load module descriptor class: Didn't find class "com.google.android.gms.dynamite.descriptors.com.google.android.gms.crash.ModuleDescriptor" on path: DexPathList[[zip file "/data/app/raphaelgrau.example.com.tabsapp-1/base.apk"],nativeLibraryDirectories=[/vendor/lib64, /system/lib64]] 
background_crash W/ResourcesManager: Asset path '/system/framework/com.android.media.remotedisplay.jar' does not exist or contains no resources. 
background_crash W/ResourcesManager: Asset path '/system/framework/com.android.location.provider.jar' does not exist or contains no resources. 
background_crash W/ResourcesManager: Asset path '/system/framework/com.android.media.remotedisplay.jar' does not exist or contains no resources. 
background_crash W/ResourcesManager: Asset path '/system/framework/com.android.location.provider.jar' does not exist or contains no resources. 
background_crash D/ChimeraCfgMgr: Reading stored module config 
background_crash I/DynamiteModule: Considering local module com.google.android.gms.crash:0 and remote module com.google.android.gms.crash:2 
background_crash I/DynamiteModule: Selected remote version of com.google.android.gms.crash, version >= 2 
background_crash D/ChimeraFileApk: Primary ABI of requesting process is x86_64 
background_crash I/art: DexFile_isDexOptNeeded failed to open oat file '/data/dalvik-cache/x86_64/data@data@com.google.android.gms@app_chimera@m@00000002@DynamiteModulesC_GmsCore_prodlmp_alldpi_release.apk@classes.dex' for file location '/data/data/com.google.android.gms/app_chimera/m/00000002/DynamiteModulesC_GmsCore_prodlmp_alldpi_release.apk': Failed to open oat filename for reading: No such file or directory 
background_crash D/ChimeraFileApk: Classloading successful. Optimized code found. 
background_crash I/FirebaseCrashReceiverServiceImpl: FirebaseCrashReceiverServiceImpl created by ClassLoader com.google.android.chimera.container.internal.DelegateLastPathClassLoader[DexPathList[[zip file "/data/data/com.google.android.gms/app_chimera/m/00000002/DynamiteModulesC_GmsCore_prodlmp_alldpi_release.apk"],nativeLibraryDirectories=[/vendor/lib64, /system/lib64]]] 
background_crash D/FirebaseCrashReceiverServiceImpl: onCreate 
background_crash I/DynamiteModule: Considering local module com.google.android.gms.flags:0 and remote module com.google.android.gms.flags:1 
background_crash I/DynamiteModule: Selected remote version of com.google.android.gms.flags, version >= 1 
background_crash I/FirebaseCrashSenderServiceImpl: FirebaseCrashSenderServiceImpl created by ClassLoader com.google.android.chimera.container.internal.DelegateLastPathClassLoader[DexPathList[[zip file "/data/data/com.google.android.gms/app_chimera/m/00000002/DynamiteModulesC_GmsCore_prodlmp_alldpi_release.apk"],nativeLibraryDirectories=[/vendor/lib64, /system/lib64]]] 
background_crash D/FirebaseCrashSenderServiceImpl: onCreate 

Answer 1

Tôi cố định vấn đề nhờ tôi để doc này:

https://codelabs.developers.google.com/codelabs/firebase-android/#6

tôi cần thêm một RecyclerView.AdapterDataObserver(): Vấn đề

mFirebaseAdapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() { 
    @Override 
    public void onItemRangeInserted(int positionStart, int itemCount) { 
     super.onItemRangeInserted(positionStart, itemCount); 
     int friendlyMessageCount = mFirebaseAdapter.getItemCount(); 
     int lastVisiblePosition = 
       mLinearLayoutManager.findLastCompletelyVisibleItemPosition(); 
     // If the recycler view is initially being loaded or the 
     // user is at the bottom of the list, scroll to the bottom 
     // of the list to show the newly added message. 
     if (lastVisiblePosition == -1 || 
       (positionStart >= (friendlyMessageCount - 1) && 
         lastVisiblePosition == (positionStart - 1))) { 
      mMessageRecyclerView.scrollToPosition(positionStart); 
     } 
    } 
}); 

đã được giải quyết!