Question

我希望从FireBase数据库中检索数据并使用自定义BaseAdapter在ListView中显示它：我有一个班级模型书：

 public class Book {

        String nom_livre;
        String desc_livre;
        String prix_livre;

        //Other Variables
        // getters and sitters

    }

自定义适配器FeedListAdapter：

public class FeedListAdapter extends BaseAdapter {

    private Activity activity;
    private LayoutInflater inflater;
    private List<Book> feedItems;

    public FeedListAdapter( Activity activity, List<Book> feedItems) {
        this.activity = activity;
        this.feedItems = feedItems;
    }

    @Override
    public int getCount() {
        return feedItems.size();
    }

    @Override
    public Object getItem(int location) {
        return feedItems.get(location);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        if (inflater == null)
            inflater = (LayoutInflater) activity
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        if (convertView == null)
            convertView = inflater.inflate(R.layout.feed_item, null);

        TextView name = (TextView) convertView.findViewById(R.id.name_book_display);
        TextView statusMsg = (TextView) convertView.findViewById(R.id.desc_livre);
        TextView prix = (TextView) convertView.findViewById(R.id.prix_display);

        Book item = feedItems.get(position);

        name.setText(item.getNom_livre());

        if (!TextUtils.isEmpty(item.getDesc_livre())) {
            statusMsg.setText(item.getDesc_livre());
            statusMsg.setVisibility(View.VISIBLE);
        } else {
            statusMsg.setVisibility(View.GONE);
        }

        if (item.getPrix_livre() != null) {
            prix.setText(item.getPrix_livre());
            prix.setVisibility(View.VISIBLE);
        } else {
            prix.setVisibility(View.GONE);
        }

        return convertView;
    }

}

更新活动：

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_accueil);
        listView = (ListView) findViewById(R.id.list);
        feedItems = new ArrayList<Book>();

 ref = FirebaseDatabase.getInstance().getReference("books");
            ref.addValueEventListener(new ValueEventListener() {
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {

                    for (DataSnapshot dataSnap : dataSnapshot.getChildren()) {

                        Book valueBook=dataSnap.getValue(Book.class);
                        String  idBookDisplay=valueBook.getId_Book();

                   if(id_user.equals(idBookDisplay)){

                       String titreLivreToDisplay=valueBook.getNom_livre();
                       String descLivreToDisplay=valueBook.getDesc_livre();
                       String prixLivreToDisplay=valueBook.getPrix_livre();
                       String timeToDisplay=valueBook.getDate_creation();
                       String filePathToDiplay=valueBook.getChemin_image();


                       Book item = new Book();

                       item.setNom_livre(titreLivreToDisplay);
                       item.setDesc_livre(descLivreToDisplay);
                       item.setPrix_livre(prixLivreToDisplay);
                       item.setDate_creation(timeToDisplay);
                       item.setChemin_image(filePathToDiplay);
                       feedItems.add(item);


                   }

                    }


                    listAdapter = new FeedListAdapter(this,feedItems);
                    listView.setAdapter(listAdapter);
                    listAdapter.notifyDataSetChanged();

                }
 });

但我有这个错误：

'FeedListAdapter(android.app.Activity, java.util.List<com.mydreambook.model.Book>)' in 'com.mydreambook.adapter.FeedListAdapter' cannot be applied to '(anonymous com.google.firebase.database.ValueEventListener, java.util.List<com.mydreambook.model.Book>)'

如何在自定义适配器中使用ValueEventListener？

使用源布局更新：

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout 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:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:openDrawer="start">
    <ListView
        android:id="@+id/list"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:divider="@null" />

    <include
        layout="@layout/app_bar_accueil"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <android.support.design.widget.NavigationView
        android:id="@+id/nav_view"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/nav_header_accueil"
        app:menu="@menu/activity_accueil_drawer" />

</android.support.v4.widget.DrawerLayout>

Answer 1

更改

beforeCreate

到

listAdapter = new FeedListAdapter(this, feedItems);

listAdapter = new FeedListAdapter(YourActivity.this, feedItems);是YourActivity的名称，您在其中调用Activity。内部addValueEventListener方法onDataChange == this，而不是ValueEventListener创建者所需的Activity

如何使用Custom baseAdapter在ListView中显示数据？

1 个答案: