如何修复片段上的 FirebaseRecyclerAdapter?

Question

我正在开发这个应用程序，我正在尝试在我的个人片段中显示我的"费用"数据库数据。我创建了一个回收器视图文件来替换默认布局。我正在努力使这项工作。任何人都可以帮助FirebaseRecycler Adapter和持有人类吗？我无法完成这项工作，我的片段显示默认布局，没有信息。我已经尝试并遵循一些代码，但它不起作用。

这是我的个人片段，其中应该出现回收器视图

package uk.brighton.ama75.project;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Adapter;
import android.widget.TextView;

import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;

import java.time.chrono.JapaneseDate;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
public class personalFragment extends Fragment {
private FirebaseAuth mAuth;
private String currentUserID;
private DatabaseReference databaseReference;
private RecyclerView recyclerView;
private Adapter adapter;

@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View myView = inflater.inflate(R.layout.fragment_personal, container, false);

mAuth = FirebaseAuth.getInstance();
currentUserID = mAuth.getCurrentUser().getUid();
databaseReference = FirebaseDatabase.getInstance().getReference().child("Expenses").child(currentUserID);
recyclerView = myView.findViewById(R.id.recycler_expense);
LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
layoutManager.setStackFromEnd(true);
layoutManager.setReverseLayout(true);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(layoutManager);

return myView;
}

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

Query query = FirebaseDatabase.getInstance()
.getReference()
.child("expenses")
.limitToLast(5);
FirebaseRecyclerOptions<PersonalExpenses> options =
new FirebaseRecyclerOptions.Builder<PersonalExpenses>()
.setQuery(query, PersonalExpenses.class)
.build();

FirebaseRecyclerAdapter adapter = new FirebaseRecyclerAdapter<PersonalExpenses, MyViewHolder>(options) {
@Override
protected void onBindViewHolder(@NonNull MyViewHolder holder, int position, @NonNull PersonalExpenses model) {

holder.setDate(model.getDate());
holder.setDescription(model.getDescription());
holder.setAmount(model.getAmount());
holder.setType(model.getType());
}
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.expense_recycler, parent, false);
return new MyViewHolder(view);
}
};
recyclerView.setAdapter(adapter);
}

@Override
public void onStop() {
super.onStop();
}

public static class MyViewHolder extends RecyclerView.ViewHolder {
private final View mView;
public MyViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
private void setDate(String date) {
TextView mDate = mView.findViewById(R.id.date_income);
mDate.setText(date);
}
private void setType(String type) {
TextView mType = mView.findViewById(R.id.type_txt);
mType.setText(type);
}
private void setDescription(String description) {
TextView mNote = mView.findViewById(R.id.note_txt);
mNote.setText(description);
}
private void setAmount(String amount) {
TextView mAmount = mView.findViewById(R.id.amount_income);
String stramount = String.valueOf(amount);
mAmount.setText(stramount);
}
}
}

这是费用回收商视图文件

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/expense_recycler"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:elevation="5dp"
app:cardElevation="5dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:orientation="horizontal">

<RelativeLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1">
<TextView
android:id="@+id/date_income"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="6 June 2019"
android:textAppearance="?android:textAppearanceSmall"
android:textStyle="bold" />

</RelativeLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="2">
<TextView
android:id="@+id/type_txt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:maxLines="1"
android:text="Type"
android:textAlignment="center"
android:textAppearance="?android:textAppearanceSmall"
android:textStyle="bold" />
<TextView
android:id="@+id/note_txt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/type_txt"
android:text="@string/description"
android:textAlignment="center"
android:textAppearance="?android:textAppearanceSmall"
android:textStyle="bold" />

</RelativeLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="3
">
<TextView
android:id="@+id/amount_income"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="0000"
android:textAlignment="center"
android:textAppearance="?android:textAppearanceSmall"
android:textStyle="bold" />

</RelativeLayout>
</LinearLayout>

</androidx.cardview.widget.CardView>

这是个人布局

<?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"
xmlns:tools="http://schemas.android.com/tools"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:background="#FFF1F3FC"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
app:cardElevation="5dp"
android:elevation="10dp"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="match_parent"
android:orientation="horizontal"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="0dp"
android:layout_weight="1"
android:gravity="center"
android:layout_margin="10dp"
android:layout_height="wrap_content"
tools:ignore="Suspicious0dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:textAppearanceMedium"
android:textColor="@android:color/black"
android:id="@+id/expenses"
android:text="expense"/>
</RelativeLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_weight="3"
android:gravity="center"
android:layout_margin="10dp"
android:layout_height="wrap_content"
tools:ignore="Suspicious0dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/expense_txt"
android:textAppearance="?android:textAppearanceMedium"
android:textColor="@android:color/black"
android:text="000.00"/>
</RelativeLayout>
</LinearLayout>

</androidx.cardview.widget.CardView>
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:id="@+id/recycler_expense"
android:layout_height="match_parent"/>
</LinearLayout>

Answer 1

我相信你缺少这两个主要代码。

在 onStart(( 中设置adapter.startListening()

在 onStop(( 中设置adapter.stopListening()

确保将代码放在 onStart(( 的范围结束之前，因为您要执行大量操作并在上面设置适配器。