Recycler View 的项目未显示

Question

The items of my recycler view is not showing. The items are retrieved from Firebase. There are no any error message or warning.

I did search relevant problems but I could not found any solution for mine. Hope someone able to correct my problem, thank you.

Here are the codes:

Layout of the recycler view data:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
app:cardElevation="5dp"
android:elevation="5dp"
android:layout_margin="5dp">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:layout_margin="5dp">

    <RelativeLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="29 November 2020"
            android:textColor="@color/date_color"
            android:textAppearance="?android:textAppearanceSmall"
            android:textStyle="bold"
            android:id="@+id/date_txt_income"
            />

    </RelativeLayout>

    <RelativeLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="2">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Type"
            android:maxLines="1"
            android:textColor="@android:color/black"
            android:textAppearance="?android:textAppearanceSmall"
            android:id="@+id/type_txt_income"
            />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Note"
            android:maxLines="1"
            android:textColor="@android:color/black"
            android:textAppearance="?android:textAppearanceSmall"
            android:layout_below="@+id/type_txt_income"
            android:id="@+id/note_txt_income"
            />

    </RelativeLayout>

    <RelativeLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="2000"
            android:textColor="@color/date_color"
            android:textAppearance="?android:textAppearanceSmall"
            android:textStyle="bold"
            android:id="@+id/amount_txt_income"
            />

    </RelativeLayout>

</LinearLayout>

</android.support.v7.widget.CardView>


Layout that shows the recycler view items:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:background="#FFF1F3FC"
tools:context=".IncomeFragment">

<android.support.v7.widget.CardView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:cardElevation="5dp"
    android:elevation="10dp">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <RelativeLayout
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center"
            android:layout_margin="10dp">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textAppearance="?android:textAppearanceMedium"
                android:textColor="@android:color/black"
                android:text="Income"
                />

        </RelativeLayout>

        <RelativeLayout
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="3"
            android:gravity="center"
            android:layout_margin="10dp">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/income_txt_result"
                android:textAppearance="?android:textAppearanceMedium"
                android:textColor="@android:color/black"
                android:text="0.00"
                />

        </RelativeLayout>

    </LinearLayout>

</android.support.v7.widget.CardView>

<android.support.v7.widget.RecyclerView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/recycler_id_income">



</android.support.v7.widget.RecyclerView>

The java file:

public class IncomeFragment extends Fragment {

//Firebase
private FirebaseAuth mAuth;
private DatabaseReference mIncomeDatabase;

//RecyclerView
private RecyclerView recyclerView;
private FirebaseRecyclerAdapter adapter;



@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View myview = inflater.inflate(R.layout.fragment_income, container, false);

    mAuth = FirebaseAuth.getInstance();

    FirebaseUser mUser = mAuth.getCurrentUser();
    String uid = mUser.getUid();

    mIncomeDatabase = FirebaseDatabase.getInstance().getReference().child("IncomeData").child(uid);

    recyclerView = myview.findViewById(R.id.recycler_id_income);

    LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());

    layoutManager.setReverseLayout(true);
    layoutManager.setStackFromEnd(true);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(layoutManager);
    return myview;
}

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

    FirebaseRecyclerOptions<Data> options = new FirebaseRecyclerOptions.Builder<Data>()
            .setQuery(mIncomeDatabase, Data.class)
            .build();

    adapter = new FirebaseRecyclerAdapter<Data, MyViewHolder>(options) {

        public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            return new MyViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.income_recycler_data, parent, false));
        }

        protected void onBindViewHolder(MyViewHolder holder, int position, @NonNull Data model) {
            holder.setAmount(model.getAmount());
            holder.setType(model.getType());
            holder.setNote(model.getNote());
            holder.setDate(model.getDate());
        }
    };

    recyclerView.setAdapter(adapter);
}
}


class MyViewHolder extends RecyclerView.ViewHolder {
View mView;

public MyViewHolder(@NonNull View itemView) {
    super(itemView);
    mView = itemView;
}

void setType(String type) {
    TextView mType = mView.findViewById(R.id.type_txt_income);
    mType.setText(type);
}

void setNote(String note) {

    TextView mNote = mView.findViewById(R.id.note_txt_income);
    mNote.setText(note);
}

void setDate(String date) {
    TextView mDate = mView.findViewById(R.id.date_txt_income);
    mDate.setText(date);
}

void setAmount(double amount) {
    TextView mAmount = mView.findViewById(R.id.amount_txt_income);
    String strAmount = String.valueOf(amount);
    mAmount.setText(strAmount);
}

}

Data.java:

public class Data {

private double amount;
private String type;
private String note;
private String id;

public Data(double amount, String type, String note, String id, String date) {
    this.amount = amount;
    this.type = type;
    this.note = note;
    this.id = id;
    this.date = date;
}

public double getAmount() {
    return amount;
}

public void setAmount(double amount) {
    this.amount = amount;
}

public String getType() {
    return type;
}

public void setType(String type) {
    this.type = type;
}

public String getNote() {
    return note;
}

public void setNote(String note) {
    this.note = note;
}

public String getId() {
    return id;
}

public void setId(String id) {
    this.id = id;
}

public String getDate() {
    return date;
}

public void setDate(String date) {
    this.date = date;
}

private String date;

public Data(){

}

}

Sorry for inappropriate format.

Answer 1

@Ryx you are missing the call to methods adapter.startListening(); and adapter.stopListening(); . I think that's why you are not getting the result. You can also look at the documentation In case you are still facing the issue then first create your own adapter and the try to run your code end to end and then use the Firebase-ui