FirebaseRecyclerAdapter 不工作或显示任何数据答案

【问题标题】：FirebaseRecyclerAdapter not working or showing any dataFirebaseRecyclerAdapter 不工作或显示任何数据
【发布时间】：2020-02-16 10:09:10
【问题描述】：

我是 Android 编程新手。我已经能够在 firebase 中创建一个 userprofile 表，并且可以在 recyclerview 中显示 userprofile 表中的用户数据，但我无法在 firebaserecyclerview 中显示名为“Arbrg”的产品表。请告诉我我在代码中做错了什么。非常感谢您的帮助。

我的代码如下：

viewARBRG.java（在按下按钮时调用）

package com.example.fb_app2;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;

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

public class viewARBRG extends AppCompatActivity {
    LinearLayoutManager mLinearLayoutManager;
    RecyclerView mRecyclerView;
    FirebaseDatabase mFirebaseDatabase;
    DatabaseReference mDatabaseReference;
    FirebaseRecyclerAdapter<MasterBarangClass, ViewHolderARBRG> firebaseRecyclerAdapter;
    FirebaseRecyclerOptions<MasterBarangClass> options;

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

    }

    @Override
    protected void onStop() {
        super.onStop();
        firebaseRecyclerAdapter.stopListening();
    }

    @Override
    public void onBackPressed() {
    }

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

        mLinearLayoutManager = new LinearLayoutManager(this);
        mLinearLayoutManager.setReverseLayout(true);
        mLinearLayoutManager.setStackFromEnd(true);

        mRecyclerView = findViewById(R.id.recyclerView_arbrg);
        mFirebaseDatabase = FirebaseDatabase.getInstance();

        showData();
    }

    private void showData() {
        mDatabaseReference = mFirebaseDatabase.getReference("Arbrg");

        options = new FirebaseRecyclerOptions.Builder<MasterBarangClass>()
                .setQuery(mDatabaseReference, MasterBarangClass.class).build();

        Toast.makeText(getApplicationContext(), "Table : " + mDatabaseReference.toString(), Toast.LENGTH_SHORT).show();

        firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<MasterBarangClass, ViewHolderARBRG>(options){
            @Override
            protected void onBindViewHolder(@NonNull ViewHolderARBRG viewHolderARBRG, int i, @NonNull MasterBarangClass masterBarangClass) {
                final String barcode = masterBarangClass.getBarcode();
                final String divbrg  = masterBarangClass.getDivbrg();
                final String hrgjual = masterBarangClass.getHrgjual();
                final String jnsbrg  = masterBarangClass.getJnsbrg();
                final String kdbrg = masterBarangClass.getKdbrg();
                final String nmbrg = masterBarangClass.getNmbrg();

                viewHolderARBRG.setDetails(viewARBRG.this,
                        masterBarangClass.getBarcode(),
                        masterBarangClass.getDivbrg(),
                        masterBarangClass.getHrgjual(),
                        masterBarangClass.getJnsbrg(),
                        masterBarangClass.getKdbrg(),
                        masterBarangClass.getNmbrg());

                viewHolderARBRG.mView.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Intent intent = new Intent(getApplicationContext(), showuser2klik.class);
                        intent.putExtra("barcode", barcode);
                        intent.putExtra("divbrg", divbrg);
                        intent.putExtra("hrgjual", hrgjual);
                        intent.putExtra("jnsbrg", jnsbrg);
                        intent.putExtra("kdbrg", kdbrg);
                        intent.putExtra("nmbrg", nmbrg);
                        startActivity(intent);
                    }
                });
            }
            @NonNull
            @Override
            public ViewHolderARBRG onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                final View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_arbrg, parent, false);

                final ViewHolderARBRG viewHolder = new ViewHolderARBRG(itemView);

                viewHolder.setOnClickListener(new ViewHolderARBRG.ClickListener() {
                    @Override
                    public void onItemClick(View view, int position) {
                        Toast.makeText(getApplicationContext(), "clicked on " +position, Toast.LENGTH_SHORT).show();
                    }

                    @Override
                    public void onItemLongClick(View view, int position) {
                        Toast.makeText(getApplicationContext(), "onItem Long click...", Toast.LENGTH_SHORT).show();
                    }
                });
                return viewHolder;
            }
        };
        mRecyclerView.setLayoutManager(mLinearLayoutManager);
        firebaseRecyclerAdapter.startListening();
        mRecyclerView.setAdapter(firebaseRecyclerAdapter);
    }

    public void back2main(View view) {
        finish();
        Intent int1 = new Intent(viewARBRG.this, MenuMasterActivity.class);
        startActivity(int1);
    }
}

activity_view_arbrg.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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".viewARBRG">

    <TextView
        android:id="@+id/textView3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="RecyclerView - MASTER BARANG VIEW" />
    <TextView
        android:id="@+id/textViewUserList"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="20dp"
        android:text="LIST BARANG (ALL)" />
    <Button
        android:id="@+id/buttonBack"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="back2main"
        android:text="BACK" />

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

MasterBarangClass.java（模型类）

package com.example.fb_app2;

public class MasterBarangClass {
    public String barcode, divbrg, hrgjual, jnsbrg,  kdbrg, nmbrg;

    public MasterBarangClass(){}

    public MasterBarangClass(String barcode, String divbrg, String hrgjual, String jnsbrg, String kdbrg, String nmbrg) {
        this.barcode = barcode;
        this.divbrg = divbrg;
        this.hrgjual = hrgjual;
        this.jnsbrg = jnsbrg;
        this.kdbrg = kdbrg;
        this.nmbrg = nmbrg;
    }

    public String getBarcode() {
        return barcode;
    }
    public void setBarcode(String barcode) {
        this.barcode = barcode;
    }

    public String getDivbrg() {
        return divbrg;
    }
    public void setDivbrg(String divbrg) {
        this.divbrg = divbrg;
    }

    public String getHrgjual() {
        return hrgjual;
    }
    public void setHrgjual(String hrgjual) {
        this.hrgjual = hrgjual;
    }

    public String getJnsbrg() {
        return jnsbrg;
    }
    public void setJnsbrg(String jnsbrg) {
        this.jnsbrg = jnsbrg;
    }

    public String getKdbrg() {
        return kdbrg;
    }
    public void setKdbrg(String kdbrg) {
        this.kdbrg = kdbrg;
    }

    public String getNmbrg() {
        return nmbrg;
    }
    public void setNmbrg(String nmbrg) {
        this.nmbrg = nmbrg;
    }
}

row_arbrg.XML（布局文件）

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="200dp"
    app:cardBackgroundColor="#fff"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    app:cardCornerRadius="3dp"
    app:cardElevation="3dp"
    app:cardUseCompatPadding="true"
    app:contentPadding="5dp"
    android:layout_margin="10dp">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp" >

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/ra_tvNmbrg"
            android:text="Nama Barang"
            android:textSize="18sp"
            android:textColor="#000"
            android:textStyle="bold"
            android:layout_marginLeft="10dp"
            android:layout_marginStart="10dp"/>

        <ImageView
            android:layout_width="110dp"
            android:layout_height="130dp"
            android:id="@+id/imageIv"
            android:src="@mipmap/ic_launcher"
            android:layout_below="@id/ra_tvNmbrg"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/ra_tvKdbrg"
            android:text="Kode Barang"
            android:textSize="18sp"
            android:textColor="#000"
            android:layout_toRightOf="@id/imageIv"
            android:layout_toEndOf="@id/imageIv"
            android:layout_marginStart="10dp"
            android:layout_marginTop="20dp"/>

        <TextView
            android:id="@+id/ra_tvBarcode"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/ra_tvKdbrg"
            android:layout_marginStart="10dp"
            android:layout_marginTop="0dp"
            android:layout_toEndOf="@id/imageIv"
            android:layout_toRightOf="@id/imageIv"
            android:text="Bar code"
            android:textColor="#000"
            android:textSize="18sp" />
        <TextView
            android:id="@+id/ra_tvHargaJual"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/ra_tvBarcode"
            android:layout_marginStart="10dp"
            android:layout_marginTop="0dp"
            android:layout_toEndOf="@id/imageIv"
            android:layout_toRightOf="@id/imageIv"
            android:text="Harga Jual"
            android:textColor="#000"
            android:textSize="18sp" />
        <TextView
            android:id="@+id/ra_tvDivBrg"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/ra_tvHargaJual"
            android:layout_marginStart="10dp"
            android:layout_marginTop="0dp"
            android:layout_toEndOf="@id/imageIv"
            android:layout_toRightOf="@id/imageIv"
            android:text="Divisi barang"
            android:textColor="#000"
            android:textSize="18sp" />
        <TextView
            android:id="@+id/ra_tvJnsBrg"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/ra_tvDivBrg"
            android:layout_marginStart="10dp"
            android:layout_marginTop="0dp"
            android:layout_toEndOf="@id/imageIv"
            android:layout_toRightOf="@id/imageIv"
            android:text="Jenis barang"
            android:textColor="#000"
            android:textSize="18sp" />
    </RelativeLayout>

</androidx.cardview.widget.CardView>

ViewHolderARBRG.java

package com.example.fb_app2;

import android.content.Context;
import android.view.View;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

public class ViewHolderARBRG extends RecyclerView.ViewHolder {
    View mView;

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

        itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mClickListener.onItemClick(view, getAdapterPosition()); }
        });

        itemView.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View view) {
                mClickListener.onItemLongClick(view, getAdapterPosition());
                return true;  }
        });
    }

    public void setDetails(Context ctx, String barcode, String divbrg, String hrgjual, String jnsbrg, String kdbrg, String nmbrg) {
        TextView mbarcode = mView.findViewById(R.id.ra_tvBarcode);
        TextView mdivbrg = mView.findViewById(R.id.ra_tvDivBrg);
        TextView mhrgjual = mView.findViewById(R.id.ra_tvHargaJual);
        TextView mjnsbrg = mView.findViewById(R.id.ra_tvJnsBrg);
        TextView mkdbrg = mView.findViewById(R.id.ra_tvKdbrg);
        TextView mnmbrg = mView.findViewById(R.id.ra_tvNmbrg);

        mbarcode.setText(barcode);
        mdivbrg.setText(divbrg);
        mhrgjual.setText(hrgjual);
        mjnsbrg.setText(jnsbrg);
        mkdbrg.setText(kdbrg);
        mnmbrg.setText(nmbrg);
    }

    private ViewHolderARBRG.ClickListener mClickListener;
    public interface ClickListener {
        void onItemClick(View view, int position);
        void onItemLongClick(View view, int position);
    }

    public void setOnClickListener(ViewHolderARBRG.ClickListener clickListener){
        mClickListener = clickListener;
    }
}

数据库结构如下：

{
  "ArBrg" : {
    "-M0CKcYgvjxeYF6sGCma" : {
      "barcode" : "001",
      "divbrg" : "Alba satu",
      "hrgjual" : "899787",
      "jnsbrg" : "ALBA",
      "kdbrg" : "AAM",
      "nmbrg" : "500000"
    }
  },
  "Arsale" : {
    "-M02z2kgntKpso966nVB" : {
      "kdsale" : "SSR",
      "nmsale" : "Showroom salesperson"
    },
    "-M02z5me5mwau1jSMtlV" : {
      "kdsale" : "ANDI",
      "nmsale" : "ANDI"
    },
    "-M02z899rEkNHbjfANi7" : {
      "kdsale" : "BUDI",
      "nmsale" : "BUDI"
    }
  },
  "DivBrg" : {
    "-M02sY8LQIykdvaQph3a" : {
      "divbrg" : "LORUS",
      "nmdivbrg" : "LORUS"
    },
    "-M02scwzlD5-iFz_7r0j" : {
      "divbrg" : "ALBA",
      "nmdivbrg" : "ALBA"
    },
    "-M02sgYbypIab-m4gTAx" : {
      "divbrg" : "SEIKO",
      "nmdivbrg" : "SEIKO"
    },
    "-M02skAS79c-xKK_xdag" : {
      "divbrg" : "ASTRON",
      "nmdivbrg" : "ASTRON"
    },
    "vSrawft4GiUgMO1Z7ZZTwaU50H42" : {
      "divbrg" : "JEMIS",
      "nmdivbrg" : "JEMIS"
    }
  },
  "JnsBrg" : {
    "-M02w-iyneYG_rjxFDj4" : {
      "divbrg" : "ALBA",
      "jnsbrg" : "AAL",
      "nmjnsbrg" : "Analog Ladies"
    },
    "-M02w3YsFzX6SWjz0z0m" : {
      "divbrg" : "ALBA",
      "jnsbrg" : "AAM",
      "nmjnsbrg" : "Analog Men"
    },
    "-M02wC9M0cjJKEKbQHJl" : {
      "divbrg" : "SEIKO",
      "jnsbrg" : "KTL",
      "nmjnsbrg" : "kinetic ladies Seiko"
    }
  },
  "UserProfil" : {
    "2GGGxrGCQkQqaK9LFIBSdJJQ22i2" : {
      "email" : "maestro.info@gmail.com",
      "name" : "budi handoyo",
      "phone" : "+6281888112576"
    },
    "9RHvuwMVbJRkxYZsx2j5f9Gqlwx1" : {
      "email" : "maestro280620@gmail.com",
      "memail" : "maestro280620@gmail.com",
      "mname" : "Api Email 2",
      "mphone" : "+6282288887529",
      "name" : "Api Email 2",
      "phone" : "+6282225397529"
    },
    "GTxmtkcY5LPBWuUK9su0JQ8Dtcv2" : {
      "email" : "celia.candr@yahoo.com",
      "name" : "celia ",
      "phone" : "+6281255082289"
    },
    "JBmBE4jd1cXARJJtzP7ZpMWi3TU2" : {
      "email" : "maestro.infosis@gmail.com",
      "memail" : "maestro.infosis@gmail.com",
      "mname" : "Andi Hidajat 2",
      "mphone" : "+6281888992276",
      "name" : "Andi Hidajat 2",
      "phone" : "+6281288972576"
    },
    "vSrawft4GiUgMO1Z7ZZTwaU50H42" : {
      "email" : "maestro_info@yahoo.com",
      "memail" : "maestro_info@yahoo.com",
      "mname" : "Andi Hidajat",
      "mphone" : "+62818902712",
      "name" : "Andi Hidajat",
      "phone" : "+628189888512"
    }
  }
}

在构建 APK 时，它没有显示任何错误，但是当我执行 viewARBRG.java 时，没有显示来自 Arbrg firebase 表的产品数据。任何帮助

问候，安迪

【问题讨论】：

你能添加你的数据库结构吗？
我更新了我的帖子并添加了数据库结构的图像。请看一看。非常感谢mucn。
我还添加了一个json格式的数据库结构。我期待着您的帮助。

标签： java android xml firebase android-recyclerview

【解决方案1】：

您的数据库引用不正确。它区分大小写。所以，请纠正它。

使用

mDatabaseReference = mFirebaseDatabase.getReference("ArBrg");

代替

mDatabaseReference = mFirebaseDatabase.getReference("Arbrg");

【讨论】：

非常感谢您的帮助。现在它正在工作。