Android Listview行重复项 [英] Android Listview row repeating item

问题描述

我有一个列表，其中我从共享首选项中获取的特定数字（位置）应显示imageview（表示当前正在播放的歌曲）。但是我得到了这个位置，但那个项目也显示在其他行上。当我滚动列表时会出现问题。

I have a list where on specific number(position) that i get from shared preferences an imageview should be shown(indicates what song is currently playing) . But i get the position,but that item is showing on other rows as well. The problem is occurring when i scroll the list.

*当我退出另一个活动时发生这种情况，并且在我的简历中我发生这样的事情：

*This is happening when i exit another activity, and on my on resume i to this:

@Override
protected void onResume() {
    super.onResume();
    if(AlbumDetails.mediaPlayer!=null)
    adapter = new PlaylistAdapter(this, songs);
    list.setAdapter(adapter);
}

这是我的代码：

public class PlaylistAdapter extends BaseAdapter {

    private Activity activity;
    private static LayoutInflater inflater = null;
    private ArrayList<Songs> data;
    private DatabaseHelper db;
    private SharedPreferences prefs;
    int playpos;

    public PlaylistAdapter(Activity a, ArrayList<Songs> songs) {
        activity = a;
        data = songs;
        db = new DatabaseHelper(a);
        inflater = (LayoutInflater) activity
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        prefs = activity.getSharedPreferences("com.darkovski.quran",
                Context.MODE_PRIVATE);
        playpos = prefs.getInt("posPlaying", -1);
    }

    public int getCount() {
        return data.size();
    }

    public Object getItem(int position) {
        return position;
    }

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

    public View getView(final int position, View convertView,
            final ViewGroup parent) {
        View vi = convertView;
        if (convertView == null)
            vi = inflater.inflate(R.layout.song_item, parent, false);

        ImageView download = (ImageView) vi
                .findViewById(R.id.playlist_item_download);
        db.openDB();
        if (db.isDownloaded(data.get(position).getNumber(), data.get(position)
                .getRecitorName(), data.get(position).getRecitorID()))
            download.setImageResource(R.drawable.download_yes);
        else {
            download.setImageResource(R.drawable.download_no);
            download.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {

                    new DownloadFileFromURL(activity, data.get(position)
                            .getRecitorName(), data.get(position).getTitle(),
                            data.get(position).getLink(), data.get(position)
                                    .getNumber(), data.get(position)
                                    .getRecitorID()).execute();
                    if (!db.isDBOpen())
                        db.openDB();
                    db.addDownloaded(data.get(position).getNumber(),
                            data.get(position).getLink(), 0, data.get(position)
                                    .getRecitorID(), "", data.get(position)
                                    .getTitle());

                    Toast.makeText(activity,
                            "Downloading " + data.get(position).getTitle(),
                            Toast.LENGTH_SHORT).show();

                }
            });
        }
        db.closeDB();

        TextView number = (TextView) vi.findViewById(R.id.playlist_item_num);
        TextView title = (TextView) vi.findViewById(R.id.playlist_item_reciter);
        title.setText(data.get(position).getTitle());
        number.setText((position + 1) + "");
        ImageView eq = (ImageView) vi.findViewById(R.id.playlist_item_equlizer);
        //this is where i show the item
        if (playpos == position) {
            eq.setVisibility(View.VISIBLE);
        }

        return vi;
    }
}

这就是它的样子：

推荐答案

因为这句话

if (playpos == position) {
        eq.setVisibility(View.VISIBLE);
    }

listview回收视图所以如果你注意到第一行和最后一行是显示相同。那是因为第一行被回收到最后一行

the listview recycles views so if you notice the first row and the last row is showing the same. That is because the first row was recycled to the last row

你可以通过在if上添加一个else来解决这个问题，看起来像

you can fix this by adding an else onto the if so it would look like

if (playpos == position) {
        eq.setVisibility(View.VISIBLE);
}else{
    eq.setVisibility(View.GONE);
}

这篇关于Android Listview行重复项的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！