在Firebase回收器适配器中，从未调用过onBindViewHolder和onCreateViewHolder吗？

Question

我正在编写一个android应用程序，需要在其中使用recycler view显示数据列表。我正在使用具有读写规则true 的firebase实时数据库，但是问题是onBindViewHolder和onCreateViewHolder从未按日志所述被调用。

模式类： ConnectedListItem.java

public class ConnectedListItem {

String name;
Double lat , lng;

public ConnectedListItem() {
}

public ConnectedListItem(String name, Double lat, Double lng) {
    this.name = name;
    this.lat = lat;
    this.lng = lng;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public Double getLat() {
    return lat;
}

public void setLat(Double lat) {
    this.lat = lat;
}

public Double getLng() {
    return lng;
}

public void setLng(Double lng) {
    this.lng = lng;
}
}

ConnectionActivity.xml：

<LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".ConnectionActivity">

<include
    android:id="@+id/connection_toolbar"
    layout="@layout/toolbar_layout" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="20dp"
    android:layout_marginBottom="15dp"
    android:fontFamily="@font/open_sans"
    android:text="Connection"
    android:textAllCaps="false"
    android:textSize="35sp"
    android:textStyle="bold" />

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_weight="1">

    <TextView
        android:id="@+id/emptyTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="No Connection"
        android:visibility="invisible" />


    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/connected_list_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

 </RelativeLayout>

 <Button
    android:id="@+id/connection_child_add_btn"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="15dp"
    android:background="@drawable/login_screen_button_background"
    android:text="Add Child"
    android:textColor="@color/white" />

 </LinearLayout>

单个用户布局： connected_single_layout.xml

<LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:background="@drawable/login_sign_up_edit_text_background"
android:orientation="vertical">

<TextView
    android:id="@+id/connectedName"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginStart="20dp"
    android:layout_marginEnd="20dp"
    android:text="Name" />

<TextView
    android:id="@+id/connectedLastLocation"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginStart="20dp"
    android:layout_marginTop="10dp"
    android:layout_marginEnd="20dp"
    android:text="Last Location" />

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="16dp"
    android:orientation="horizontal"
    android:weightSum="2">

    <Button
        android:id="@+id/removeBtn"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="6dp"
        android:layout_weight="1"
        android:text="Remove" />

    <Button
        android:id="@+id/trackB only oncetn"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="6dp"
        android:layout_weight="1"
        android:text="Track" />

</LinearLayout>

</LinearLayout>

ConnecttionActivity.java：

public class ConnectionActivity extends AppCompatActivity {

private String TAG = "ConnectionActivity";

private RecyclerView mChildConnectedListRecyclerView;
private androidx.appcompat.widget.Toolbar mToolbar;

private TextView mEmptyTextView;

private DatabaseReference mConnectedUserDatabase , mUserDatabase;
private FirebaseAuth mAuth;
private String mCurrentUser;

private Button mAddChildBtn;

private Geocoder geocoder;

FirebaseRecyclerAdapter<ConnectedListItem , ConnectedViewHolder> adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_connection);

    Log.d(TAG, "onCreate: called");

    mAuth = FirebaseAuth.getInstance();

    setUpToolbar();

    if(mAuth.getCurrentUser() != null){
        mCurrentUser = mAuth.getCurrentUser().getUid();
        Log.d("CurrentUser", mCurrentUser);
    }

    mAddChildBtn = (Button) findViewById(R.id.connection_child_add_btn);
    mConnectedUserDatabase = FirebaseDatabase.getInstance().getReference().child("Connected").child(mCurrentUser);

    Log.d(TAG, "onCreate: " + mCurrentUser);

    mUserDatabase = FirebaseDatabase.getInstance().getReference().child("Users");

    mChildConnectedListRecyclerView = (RecyclerView) findViewById(R.id.connected_list_view);
    mChildConnectedListRecyclerView.setHasFixedSize(true);
    mChildConnectedListRecyclerView.setLayoutManager(new LinearLayoutManager(this));


    mEmptyTextView = (TextView) findViewById(R.id.emptyTextView);

    mAddChildBtn.setOnClickListener(v -> {

        // Some code here

    });

}

 @Override
 protected void onStart() {
    super.onStart();

    Log.d(TAG, "onStart: called");

    FirebaseRecyclerOptions options = new FirebaseRecyclerOptions.Builder<ConnectedListItem>()
                                                .setQuery(mConnectedUserDatabase , ConnectedListItem.class)
                                                .build();

    Log.d(TAG, "onStart: Firebase option done");

    adapter = new FirebaseRecyclerAdapter<ConnectedListItem, ConnectedViewHolder>(options) {
                @Override
                protected void onBindViewHolder(@NonNull ConnectedViewHolder connectedViewHolder, int i, @NonNull ConnectedListItem connectedListItem) {


                    Log.d(TAG, "onBindViewHolder: called" + connectedListItem.getName());

                     connectedViewHolder.mChildName.setText(connectedListItem.getName());

                    Double mLat = connectedListItem.getLat();
                    Double mLng = connectedListItem.getLng();

                    // geocoding starts here
                    String errorMessage = "";

                    geocoder = new Geocoder(getApplicationContext(), Locale.getDefault());

                    List<Address> addresses = null;

                    try {
                        addresses = geocoder.getFromLocation(
                                    mLat,
                                    mLng,
                                // In this sample, get just a single address.
                                1);
                    } catch (IOException e) {
                        errorMessage = getString(R.string.service_not_available);
                        Log.e(TAG, errorMessage, e);
                    } catch (IllegalArgumentException illegalArgumentException) {
                        // Catch invalid latitude or longitude values.
                        errorMessage = getString(R.string.invalid_lat_long_used);
                        Log.e(TAG, errorMessage + ". " +
                                "Latitude = " + mLat +
                                ", Longitude = " +
                                mLng, illegalArgumentException);
                    }

                    // Handle case where no address was found.
                    if (addresses == null || addresses.size() == 0) {
                        if (errorMessage.isEmpty()) {
                            errorMessage = getString(R.string.no_address_found);
                            Log.e(TAG, errorMessage);
                        }

                    } else {
                    Address address = addresses.get(0);
                        ArrayList<String> addressFragments = new ArrayList<String>();

                        // Fetch the address lines using getAddressLine,
                        // join them, and send them to the thread.
                        for (int j = 0; j <= address.getMaxAddressLineIndex(); j++) {
                            addressFragments.add(address.getAddressLine(j));
                        }
                        // Log.i(TAG, getString(R.string.address_found));

                        connectedViewHolder.mChildAddress.setText(TextUtils.join(System.getProperty("line.separator"),
                                addressFragments));

                    }

                }

                @NonNull
                @Override
                public ConnectedViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

                    Log.d(TAG, "onCreateViewHolder: called");

                    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.connected_single_layout , parent, false);

                    ConnectedViewHolder connectedViewHolder = new ConnectedViewHolder(view);


                    return connectedViewHolder;
                }

        @Override
        public int getItemCount() {
            return super.getItemCount();
        }
    };

    mChildConnectedListRecyclerView.setAdapter(adapter);

    Log.d(TAG, "onStart: Adapter setuped");
    adapter.startListening();
    Log.d(TAG, "onStart: Start listening called");

}

@Override
protected void onDestroy() {
    super.onDestroy();

    adapter.stopListening();

    Log.d(TAG, "onDestroy: Called Stop");
}

@Override
protected void onStop() {
    super.onStop();

    adapter.stopListening();
}

@Override
protected void onResume() {
    super.onResume();

    adapter.startListening();

    Log.d(TAG, "onResume: called resume");
}

public static class ConnectedViewHolder extends RecyclerView.ViewHolder {

    TextView mChildName , mChildAddress;

    Button mTrackBtn , mRemoveBtn;

    private ConnectedViewHolder(@NonNull View itemView) {
        super(itemView);

        mChildAddress = itemView.findViewById(R.id.connectedLastLocation);
        mChildName = itemView.findViewById(R.id.connectedName);

        mTrackBtn = (Button) itemView.findViewById(R.id.trackBtn);
        mRemoveBtn = (Button) itemView.findViewById(R.id.removeBtn);
    }

}
}

应用程序级build.gradle：

//Firebase dependencies here
implementation 'com.google.firebase:firebase-core:16.0.9'
implementation 'com.google.firebase:firebase-auth:17.0.0'
implementation 'com.google.firebase:firebase-database:17.0.0'
implementation 'com.firebaseui:firebase-ui-database:5.0.0'

Logcat：

ConnectionActivity: onCreate: called
ConnectionActivity: onCreate: 8zQPcYnUHnQBtRetg4vkylXJI1O2
ConnectionActivity: onStart: called
ConnectionActivity: onStart: Firebase option done
ConnectionActivity: onStart: Adapter setuped
ConnectionActivity: onStart: Start listening called
ConnectionActivity: onResume: called resume
Logging event (FE): screen_view(_vs), 
           Bundle[{firebase_event_origin(_o)=auto, 
           firebase_previous_class(_pc)=ParentHomeActivity, 
           firebase_previous_id(_pi)=4706309106774484658, 
           firebase_screen_class(_sc)=ConnectionActivity, 
           firebase_screen_id(_si)=4706309106774484659}]
Logging event (FE): user_engagement(_e), 
           Bundle[{firebase_event_origin(_o)=auto, 
                   engagement_time_msec(_et)=8849, 
           firebase_screen_class(_sc)=ConnectionActivity, 
           firebase_screen_id(_si)=4706309106774484659}]
Logging event (FE): screen_view(_vs), 
           Bundle[{firebase_event_origin(_o)=auto, 
           firebase_previous_class(_pc)=ConnectionActivity, 
           firebase_previous_id(_pi)=4706309106774484659, 
           firebase_screen_class(_sc)=ParentHomeActivity, 
           firebase_screen_id(_si)=4706309106774484658}]
ConnectionActivity: onDestroy: Called Stop

我在stackOverflow上搜索了其他问题，但没有一个对我有用。请帮助

Answer 1

我终于通过删除此行mChildConnectedListRecyclerView.setHasFixedSize(true);

解决了该问题