Question

我正致力于在BaseAdapter的getView（）方法中动态检索所有音频文件（使用album-art）的应用程序。

现在如何删除listView上的项目。（例如，如果我点击listView的第3项，则应删除或删除第3项）。

music_cursor代码：

String[] proj = { MediaStore.Audio.Media._ID,
        MediaStore.Audio.Media.DATA,
        MediaStore.Audio.Media.DISPLAY_NAME,
        MediaStore.Video.Media.SIZE, MediaStore.Audio.Media.ARTIST,
        MediaStore.Audio.Media.ALBUM_ID, MediaStore.Audio.Media.TITLE };

Cursor musiccursor = managedQuery(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
        proj, null, null, null);
int count = musiccursor.getCount();

适配器代码：

public class MusicAdapter extends BaseAdapter {
        private Context mContext;

        public MusicAdapter(Context con) {
            mContext = con;
        }
        public int getCount() {
            return count;
        }
        public Object getItem(int position) {
            return position;
        }
        public long getItemId(int position) {
            return position;
        }

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

            String id = null;
            ViewHolder holder;
            LayoutInflater inflater = getLayoutInflater();

            if (convertView == null) {

                convertView = inflater.inflate(R.layout.sub_layout, null);
                holder = new ViewHolder();

                holder.ID_ = (TextView) convertView.findViewById(R.id.txtSongName);
                holder.SIZE_ = (TextView) convertView.findViewById(R.id.txtSongSize);
                holder.ARTIST = (TextView) convertView.findViewById(R.id.txtSongArtist);
                holder.TITLE_image = (ImageView) convertView.findViewById(R.id.imgArtWork);

                convertView.setTag(holder);
            } else {
                holder = (ViewHolder) convertView.getTag();
            }

            // code for retrieving audio name and set to textView
            music_column_index = musiccursor
                    .getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME);
            musiccursor.moveToPosition(position);
            id = musiccursor.getString(music_column_index);
            holder.ID_.setText(id);
            holder.ID_.setTextSize(15);

            // code for retrieving audioSize and set to textView
            music_column_index = musiccursor
                    .getColumnIndexOrThrow(MediaStore.Audio.Media.SIZE);
            musiccursor.moveToPosition(position);
            id = (musiccursor.getString(music_column_index) + " (KB)");
            holder.SIZE_.setText(id);
            holder.SIZE_.setTextSize(15);

            // code for retrieving audio_Artist name and set to textView
            music_column_index = musiccursor
                    .getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST);
            musiccursor.moveToPosition(position);
            id = musiccursor.getString(music_column_index);
            holder.ARTIST.setText(id);
            holder.ARTIST.setTextSize(15);

            // code for retrieving album-art(from albumid) and set to ImageView

            musiccursor.moveToPosition(position);
            album_id_long = musiccursor.getLong(musiccursor
                    .getColumnIndexOrThrow(MediaStore.Audio.Media.ALBUM_ID));

            Uri sArtworkUri = Uri.parse("content://media/external/audio/albumart");
            Uri uri = ContentUris.withAppendedId(sArtworkUri, album_id_long);
            ContentResolver res = MusicActivity.this.getContentResolver();
            InputStream in = null;
            try {
                in = res.openInputStream(uri);
            } catch (FileNotFoundException e1) {
                e1.printStackTrace();
            }
            Bitmap artwork = BitmapFactory.decodeStream(in);

            holder.TITLE_image.setImageBitmap(artwork);

            convertView.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {

                    //on this code of onClick,a selected item should be deleted

                }
            });

            return convertView;
        }

        private class ViewHolder {
            TextView ID_;
            TextView SIZE_;
            TextView ARTIST;
            ImageView TITLE_image;
        }
    }

enter image description here

如果还有其他方法可以做到这一点。我们将非常感激。

感谢。

Answer 1

你必须覆盖

public void onListItemClick(ListView l, View v, int position, long id)

单击视图时，将调用此回调。调用它时，您可以从数据库中删除该条目，然后重新运行您创建的查询以填满ListView。如果您要Activity而不是ListActivity，则必须设置OnItemClickListener

yourListView.setOnItemClickListener(
    new OnItemClickListener()
    {
        @Override
        public void onItemClick(AdapterView<?> arg0, View view,
                int position, long id) {


             }
        }
 );

Answer 2

您是否真的要删除音乐文件或只是将其从ListView中删除？顺便说一下，你只需要打电话 “musiccursor.moveToPosition（位置）;” 一旦开始

使用listview删除BaseAdapter中的ConvertView运行时

2 个答案: