如何从 Cloud Firestore 获取数据并使用回收站视图显示

Question

我有一个云 Firestore 数据库，其中包含一个名为 Bus 的集合和其中的三个文档，如图所示 database picture
我已按照此链接中的内容进行操作 How to display data from Firestore in a RecyclerView with Android?

正在创建和显示三个回收站视图，但数据为空 同样，当我将第四个文档添加到 Bus 时，正在创建和显示四个回收站视图，但数据为空

你能告诉我如何修复我的代码吗？

型号：

public class Bus {
    public Bus(String driverName, int busNo, String contactNo) {
        this.driverName = driverName;
        this.busNo = busNo;
        this.contactNo = contactNo;
    }

    public Bus(){ }
    public String getDriverName() {
        return driverName;
    }

    public void setDriverName(String driverName) {
        this.driverName = driverName;
    }

    public int getBusNo() {
        return busNo;
    }

    public void setBusNo(int busNo) {
        this.busNo = busNo;
    }

    public String getContactNo() {
        return contactNo;
    }

    public void setContactNo(String contactNo) {
        this.contactNo = contactNo;
    }

    String driverName, contactNo;
    int busNo ;
}

活动代码：

public class ViewBusDetailes   extends AppCompatActivity  {
    LinearLayoutManager linearLayoutManager;
    FirestoreRecyclerAdapter<Bus, BusViewHolder> adapter;
    class BusViewHolder extends RecyclerView.ViewHolder {
        private View view;

        BusViewHolder(View itemView) {
            super(itemView);
            view = itemView;
        }

        void setDetiles(String contactNoText , String driverNameText, int busNoText) {
            TextView driverName;
            TextView busNo;
            TextView contactNo;
            driverName = itemView.findViewById(R.id.driverNameDriverListView);
            contactNo = itemView.findViewById(R.id.driverContactDriverListView);
            busNo = itemView.findViewById(R.id.busNumber);
            driverName.setText(driverNameText);
            busNo.setText(String.valueOf(busNoText));
            contactNo.setText(contactNoText);
        }
    }
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_view_bus_details__layout);
        RecyclerView recyclerView = findViewById(R.id.recyclerView);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
        Query query = rootRef.collection("Bus");

        FirestoreRecyclerOptions<Bus> options = new FirestoreRecyclerOptions.Builder<Bus>()
                .setQuery(query, Bus.class)
                .build();


        adapter = new FirestoreRecyclerAdapter<Bus, BusViewHolder>(options) {
            @Override
            protected void onBindViewHolder(@NonNull BusViewHolder holder, int position, @NonNull Bus model) {
                holder.setDetiles(model.getContactNo() , model.getDriverName() ,model.getBusNo());
            }

            @NonNull
            @Override
            public BusViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.bus_list_view, parent, false);
                return new BusViewHolder(view);
            }
        };
        recyclerView.setAdapter(adapter);
    }

    protected void onStart() {
        super.onStart();
        adapter.startListening();
    }

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

        if (adapter != null) {
            adapter.stopListening();
        }
    }
}

bus_list_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="360dp"
    android:layout_height="72dp"
    android:background="?android:attr/selectableItemBackground"
    android:orientation="horizontal"
    android:padding="16dp">

    <TextView

        android:id="@+id/busNumber"
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:textSize="20sp"
        android:gravity="center"
        android:fontFamily="sans-serif"
        android:textStyle="normal"
        android:textColor="#ffffff"
        android:background="@drawable/circle"
        />

    <LinearLayout
        android:layout_width="287dp"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <TextView
            android:id="@+id/driverNameDriverListView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="16dp"
            android:textSize="17sp"
            android:fontFamily="sans-serif"
            android:textStyle="normal"
            android:textColor="#de000000"
            android:lineSpacingExtra="8sp"
            android:text="Anwar"

            />


        <TextView
            android:id="@+id/driverContactDriverListView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="14sp"
            android:layout_marginLeft="17dp"
            android:fontFamily="sans-serif"
            android:textStyle="normal"
            android:textColor="#de000000"
            android:lineSpacingExtra="6sp"
            android:text="Dude can you solve this problem plea..."

            />


    </LinearLayout>

</LinearLayout>

activity_view_bus_detiels.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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"
    tools:context=".activity.ViewBusDetailes"
    android:id="@+id/container">

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

Answer 1

这样做

public class Bus {
    private String driverName;
    private int busNo;
    private String contactNo;

    public String getDriverName() {
        return driverName;
    }

    public int getBusNo() {
        return busNo;
    }

    public String getContactNo() {
        return contactNo;
    }
}

活动代码：

public class ViewBusDetailes extends AppCompatActivity  {
    LinearLayoutManager linearLayoutManager;
    FirestoreRecyclerAdapter adapter;

    class BusViewHolder extends RecyclerView.ViewHolder {
        TextView driverName;
        TextView busNo;
        TextView contactNo;

        BusViewHolder(View itemView) {
            super(itemView);
            driverName = itemView.findViewById(R.id.driverNameDriverListView);
            contactNo = itemView.findViewById(R.id.driverContactDriverListView);
            busNo = itemView.findViewById(R.id.busNumber);
        }
    }

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_view_bus_details__layout);
        RecyclerView recyclerView = findViewById(R.id.recyclerView);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
        Query query = rootRef.collection("Bus");

        FirestoreRecyclerOptions<Bus> options = new FirestoreRecyclerOptions.Builder<Bus>()
                .setQuery(query, Bus.class)
                .build();


        adapter = new FirestoreRecyclerAdapter<Bus, BusViewHolder>(options) {
            @Override
            protected void onBindViewHolder(@NonNull BusViewHolder holder, int position, @NonNull Bus model) {

                holder.driverName.setText(model.getDriverName());
                holder.busNo.setText(String.valueOf(model.getBusNo()));
                holder.contactNo.setText(model.getContactNo());
            }

            @NonNull
            @Override
            public BusViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                View view = LayoutInflater.from(ViewBusDetailes.this).inflate(R.layout.bus_list_view, parent, false);
                return new BusViewHolder(view);
            }
        };
        recyclerView.setAdapter(adapter);
    }

    protected void onStart() {
        super.onStart();
        adapter.startListening();
    }

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

        if (adapter != null) {
            adapter.stopListening();
        }
    }
}

另外，如果你还没有添加这个依赖项。

implementation 'com.firebaseui:firebase-ui-firestore:4.3.2'

另外，在 Firebase 控制台的 Firestore 设置中编辑您的 Firebase Firestore 规则。

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if true;
    }
  }
}

检查它是否有效。