Not Getting Data From Firebase on ListView With FirebaseListAdapter

问题

The Problem with this code is that the data is not showing in listview and the app is also not showing any error. I am initializing this model class from some other activity, so please any one can give me suggestion about what would be the real problem.

public class FireBaseListAdapter extends AppCompatActivity {

    private ListView mlistview;

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

        mlistview = (ListView)findViewById(R.id.firebase_list);

      //  DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference();

        final Query query = getInstance().getReference();

        FirebaseListOptions<Users> options = new FirebaseListOptions.Builder<Users>().setQuery(query,Users.class).setLayout(R.layout.listview_for_firebaselistadapter).build();

        FirebaseListAdapter<Users> firebaseListAdapter = new FirebaseListAdapter<Users>(options) {
            @Override
            protected void populateView(View v, Users model, int position) {
                model = getItem(position);
                TextView textViewname = (TextView)v.findViewById(R.id.listAdapter_nametext);
                TextView textViewplace = (TextView)v.findViewById(R.id.listAdapter_placetext);

                textViewname.setText(model.getName());
                textViewplace.setText(model.getPlace());
            }
        };
        mlistview.setAdapter(firebaseListAdapter);
    }
}

This is My Model Class:

    public class Users {

    private String name;
    private String place;

    public Users() {
    }

    public Users(String name, String place) {
        this.name = name;
        this.place = place;
    }

    public String getName() {
        return name;
    }

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

    public String getPlace() {
        return place;
    }

    public void setPlace(String place) {
        this.place = place;
    }
}

This is My XML containing two textView

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

    <TextView
        android:id="@+id/listAdapter_nametext"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Driver Name"
        android:textSize="25sp"/>
    <TextView
        android:id="@+id/listAdapter_placetext"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Driver Place"
        android:textSize="25sp"/>

</LinearLayout>

回答1:

It seems to you forgot to pass reference in your query

final Query query = getInstance().getReference();

// Create a reference to the cities collection
CollectionReference citiesRef = db.collection("cities");

// Create a query against the collection.
Query query = citiesRef.whereEqualTo("state", "CA");

Reference

回答2:

To solve this, you need to override the onStart() method and add the following line of code:

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

But first don't forget to make the firebaseListAdapter variable global.

private FirebaseListAdapter<Users> firebaseListAdapter;

And then just remove FirebaseListAdapter<Users> where you intialize the adapter.

来源：https://stackoverflow.com/questions/49313035/not-getting-data-from-firebase-on-listview-with-firebaselistadapter

标签

android

android-layout

listview

firebase-realtime-database

android-adapter