Question

我试图在片段中对listview应用数据绑定，但它不起作用，这是片段的onCreateView方法，其中是膨胀：

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    SongListBinding songList = DataBindingUtil.inflate(inflater, R.layout.song_list, container, false);



    View rootView = inflater.inflate(R.layout.song_list, container, false);

    audioManager = (AudioManager) getActivity().getSystemService(Context.AUDIO_SERVICE);

    final ArrayList<Song> songs = new ArrayList<Song>();

    //Here I'm populating the ArrayList 

    SongAdapter adapter = new SongAdapter (getActivity(),  songs);

    songList.list.setAdapter(adapter);

    songList.list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {

            releaseMediaPlayer();
            Song song = songs.get(position);
            int result = audioManager.requestAudioFocus(mOnAudioFocusChangeListener,
                    AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);

            if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
                mediaPlayer = MediaPlayer.create(getActivity(), song.getmAudioResourceId());

                mediaPlayer.start();
                 mediaPlayer.setOnCompletionListener(mCompletionListener);
            }

        }
    });

    return rootView;
}

但是列表视图没有显示，我不明白为什么，listview xml文件是：

<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<ListView
    android:id="@+id/list"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:drawSelectorOnTop="true"
    /></layout>

我也尝试过这样做：

SongListBinding songList = DataBindingUtil.inflate(LayoutInflater.from(getContext()), R.layout.song_list, null, false);

但这不起作用

你能帮帮我吗？

这是我的SongAdapter java类：

public class SongAdapter extends ArrayAdapter<Song> {

public SongAdapter (Activity context , ArrayList<Song> songs){

    super(context, 0,songs);

}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // Check if the existing view is being reused, otherwise inflate the view
    View listItemView = convertView;
    if(listItemView == null) {
        listItemView = LayoutInflater.from(getContext()).inflate(
                R.layout.list_item, parent, false);
    }
    // Get the {@link Song} object located at this position in the list
    Song currentSong = getItem(position);


    ListItemBinding listItem = DataBindingUtil.inflate(LayoutInflater.from(getContext()), R.layout.list_item, null, false);

    //Get the title of the song from the current Song object and
    //set this text on the song title TextView
    listItem.titleTextView.setText(currentSong.getmSongTitle());

    //Get the artist of the song from the current Song object and
    //set this text on the song artist TextView

    if (currentSong.hasArtist()) {

        listItem.artistTextView.setText(currentSong.getmSongArtist());
    } else {

        listItem.artistTextView.setText(R.string.unkown_artist);
    }

    // Return the whole list item layout (containing 2 TextViews and an ImageView)
    // so that it can be shown in the ListView
    return listItemView;
}

}

Answer 1

我不是100％肯定，但我的猜测是你应该调用父构造函数，如：

public SongAdapter (Activity context, ArrayList<Song> songs){
    super(context, R.layout.list_item, songs); // pass layout id like this
}

此外，您不应该两次充气。像这样使用DataBindingUtil：

ListItemBinding listItem = DataBindingUtil.bind(listItemView);

问题可能是错误的绑定数据到未使用的视图，但尝试两种解决方案。希望它有所帮助。

我试图为列表视图进行数据绑定，但它不起作用

1 个答案: