获取用户数据时，Firebase RecyclerView崩溃

Question

我刚开始使用Java编程，在这个应用程序上我已经创建了注册和登录，但是现在我试图在RelativeLayout内的TextView上显示每个登录用户的姓名和年龄。

我正在使用RecyclerView来膨胀具有TextView的RelativeLayout，其中将包含用户信息，但是当我编写所​​有代码并对其进行编译时，它将使应用程序崩溃。

我希望我已经足够清楚了，即使不只是问我，我也会尝试提供更多细节。

我的 MainActivity.java

package com.pap.diogo.pilltrack;

import android.accounts.Account;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.BottomNavigationView;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.text.Layout;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.RelativeLayout;
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.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import org.w3c.dom.Text;

public class MainActivity extends AppCompatActivity {

    private RelativeLayout pills_layout, appoint_layout, add_pills_layout, add_appoints_layout, account_layout, add_button;
    private View pills, appointments, add_pills, add_appoints, account;
    private TextView AccountName0, AccountAge0;
    private RecyclerView AccountUsers;


    private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
            = new BottomNavigationView.OnNavigationItemSelectedListener() {

        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {
            switch (item.getItemId()) {
                case R.id.navigation_home:
                    Home();
                    return true;
                case R.id.navigation_pills:
                    Pills();
                    return true;
                case R.id.navigation_appointment:
                    Appointment();
                    return true;
                case R.id.navigation_account:
                    Account();
                    return true;
            }
            return false;
        }
    };

    public MainActivity() {
    }

    private void Account(){
       RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) add_button.getLayoutParams();
        params.addRule(RelativeLayout.BELOW, R.id.account);

        pills_layout.removeView(pills);
        appoint_layout.removeView(appointments);
        add_pills_layout.removeView(add_pills);
        add_appoints_layout.removeView(add_appoints);

        //account_layout.removeAllViews();
        //account_layout.addView(account);

        add_button.setVisibility(View.VISIBLE);
        getUserInfo();

    }


    private void Appointment() {
        RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) add_button.getLayoutParams();
        params.addRule(RelativeLayout.BELOW, R.id.add_appoints);

        pills_layout.removeView(pills);
        appoint_layout.removeView(appointments);
        add_pills_layout.removeView(add_pills);
        account_layout.removeView(account);

        add_appoints_layout.removeAllViews();
        add_appoints_layout.addView(add_appoints);

        add_button.setVisibility(View.VISIBLE);
    }

    private void Pills() {
        RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) add_button.getLayoutParams();
        params.addRule(RelativeLayout.BELOW, R.id.add_pills);

        pills_layout.removeView(pills);
        appoint_layout.removeView(appointments);
        add_appoints_layout.removeView(add_appoints);
        account_layout.removeView(account);

        add_pills_layout.removeAllViews();
        add_pills_layout.addView(add_pills);

        add_button.setVisibility(View.VISIBLE);
    }

    private void Home() {
        add_appoints_layout.removeView(add_appoints);
        add_pills_layout.removeView(add_pills);
        account_layout.removeView(account);

        pills_layout.removeAllViews();
        pills_layout.addView(pills);

        appoint_layout.removeAllViews();
        appoint_layout.addView(appointments);

        add_button.setVisibility(View.GONE);
    }

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

        pills_layout = findViewById(R.id.pills_layout);
        appoint_layout = findViewById(R.id.appoint_layout);
        add_pills_layout = findViewById(R.id.add_pills);
        add_appoints_layout = findViewById(R.id.add_appoints);
        account_layout = findViewById(R.id.account);
        add_button = findViewById(R.id.add);
        AccountName0 = findViewById(R.id.AccountName0);
        AccountAge0 = findViewById(R.id.AccountAge0);

        LayoutInflater inflater = (LayoutInflater) getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        pills = inflater.inflate(R.layout.pills, null);
        appointments = inflater.inflate(R.layout.appointments, null);
        add_pills = inflater.inflate(R.layout.add_pills, null);
        add_appoints = inflater.inflate(R.layout.add_appoint, null);
        account = inflater.inflate(R.layout.account, null);

        pills_layout.addView(pills);
        appoint_layout.addView(appointments);

        add_button.setVisibility(View.GONE);

        BottomNavigationView navigation = findViewById(R.id.navigation);
        navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
    }

    public void getUserInfo(){
        AccountUsers = findViewById(R.id.AccountList);
        AccountUsers.setHasFixedSize(true);
        AccountUsers.setLayoutManager(new LinearLayoutManager(getBaseContext()));

        FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
        final String userid = user.getUid();

        final DatabaseReference ref = FirebaseDatabase.getInstance().getReference("Users");

        FirebaseRecyclerOptions<AccountLayout> AccountQ = new FirebaseRecyclerOptions.Builder<AccountLayout>().setQuery(ref, AccountLayout.class).setLifecycleOwner(this).build();

        FirebaseRecyclerAdapter<AccountLayout, AccountInfo> AccountAdapter = new FirebaseRecyclerAdapter<AccountLayout, AccountInfo>(AccountQ){

            @NonNull
            @Override
            public AccountInfo onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
                return new AccountInfo(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.account_layout, viewGroup, false));
            }

            @Override
            protected void onBindViewHolder(@NonNull final AccountInfo holder, int position, @NonNull final AccountLayout model) {
                ref.child(userid).addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                        final String name = dataSnapshot.child("name").getValue().toString();
                        final String age = dataSnapshot.child("idade").getValue().toString();
                        holder.setName(name);
                        holder.setAge(age);
                    }

                    @Override
                    public void onCancelled(@NonNull DatabaseError databaseError) {

                    }
                });
            }


        };
        AccountUsers.setAdapter(AccountAdapter);
    }

    public static class AccountInfo extends RecyclerView.ViewHolder{
        View AccountL;

        public AccountInfo(@NonNull View itemView) {
            super(itemView);

            AccountL = itemView;
        }

        public void setName(String name){
            TextView AccountName = AccountL.findViewById(R.id.AccountName0);
            AccountName.setText(name);
        }

        public void setAge(String age){
            TextView AccountAge = AccountL.findViewById(R.id.AccountAge0);
            AccountAge.setText(age);
        }
    }
}

我的 AccountLayout.java

package com.pap.diogo.pilltrack;

public class AccountLayout {
    private String name, idade;

    public AccountLayout() {

    }

    public AccountLayout(String name, String idade) {
        this.name = name;
        this.idade = idade;
    }

    public String getName() {
        return name;
    }

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

    public String getIdade() {
        return idade;
    }

    public void setIdade(String idade) {
        this.idade = idade;
    }
}

我的 account.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent">

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

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

</LinearLayout>

我的 account_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <RelativeLayout
        android:id="@+id/AccountUser"
        android:layout_width="match_parent"
        android:layout_height="163dp"
        android:layout_marginStart="15dp"
        android:layout_marginLeft="15dp"
        android:layout_marginTop="15dp"
        android:layout_marginEnd="15dp"
        android:layout_marginRight="15dp"
        android:layout_marginBottom="15dp"
        android:background="@drawable/edit_bg"
        android:padding="15dp">

        <RelativeLayout
            android:id="@+id/AccountImage"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">

            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:src="@drawable/ic_user"/>

        </RelativeLayout>

        <RelativeLayout
            android:id="@+id/AccountInfos"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_toRightOf="@id/AccountImage"
            android:layout_toEndOf="@id/AccountImage"
            android:layout_marginStart="15dp"
            android:layout_marginLeft="15dp">

            <TextView
                android:id="@+id/AccountName0"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingTop="5dp"
                android:paddingBottom="5dp"
                android:text="Nome1"
                android:textColor="@color/colorWhite"
                android:textSize="20sp"
                android:textStyle="bold" />

            <TextView
                android:id="@+id/AccountAge0"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_below="@+id/AccountName0"
                android:paddingTop="5dp"
                android:paddingBottom="5dp"
                android:text="Idade1"
                android:textColor="@color/colorWhite"
                android:textSize="20sp"
                android:textStyle="bold" />

            <Button
                android:id="@+id/AccountChangePass"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_below="@+id/AccountAge0"
                android:text="Mudar Palavra-Passe"
                android:textColor="@color/colorWhite"
                android:textSize="18sp"
                android:textStyle="bold"
                android:textAllCaps="false"
                android:padding="10dp"
                android:layout_marginTop="10dp"
                android:background="@drawable/change_password"/>
        </RelativeLayout>

    </RelativeLayout>

</RelativeLayout>

我的 Logcat

2019-02-22 17:26:43.872 12425-12425/com.pap.diogo.pilltrack E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.pap.diogo.pilltrack, PID: 12425
    java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView.setHasFixedSize(boolean)' on a null object reference
        at com.pap.diogo.pilltrack.MainActivity.getUserInfo(MainActivity.java:162)
        at com.pap.diogo.pilltrack.MainActivity.Account(MainActivity.java:80)
        at com.pap.diogo.pilltrack.MainActivity.access$300(MainActivity.java:33)
        at com.pap.diogo.pilltrack.MainActivity$1.onNavigationItemSelected(MainActivity.java:57)
        at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:204)
        at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:840)
        at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:158)
        at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:991)
        at android.support.design.internal.BottomNavigationMenuView$1.onClick(BottomNavigationMenuView.java:115)
        at android.view.View.performClick(View.java:6597)
        at android.view.View.performClickInternal(View.java:6574)
        at android.view.View.access$3100(View.java:778)
        at android.view.View$PerformClick.run(View.java:25885)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6669)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)