在列表视图中按字母顺序排列查询的音乐文件

Question

好的，所以我正在为安卓制作媒体播放器应用程序。 直到现在一切都很好。 到目前为止，我有一个列表视图，显示SD卡上的所有.mp3文件（内部和外部），并在播放时显示音乐可视化工具。 但我不能一辈子按字母顺序排列列表。 一切都是动态的，所以XML在这里不起作用。

 public class MusicPlayerActivity extends Activity {
  ListView musiclist;
  Cursor musiccursor;
  int music_column_index;
  int count;
  private Intent aIntent;
  public static String filename;
  private RelativeLayout mRelativeLayout;

  @Override
  public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        init_phone_music_grid();
        mRelativeLayout = new RelativeLayout(this);
        setContentView(mRelativeLayout);
        mRelativeLayout.addView(musiclist);
  }
  public void init_phone_music_grid() {
        System.gc();
        String[] projection = {
                MediaStore.Audio.Media._ID,
                MediaStore.Audio.Media.ARTIST,
                MediaStore.Audio.Media.TITLE,
                MediaStore.Audio.Media.DATA,
                MediaStore.Audio.Media.DISPLAY_NAME,
                MediaStore.Audio.Media.DURATION,
                MediaStore.Audio.Media.ALBUM
        };
        Uri allsongsuri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0";
        musiccursor = managedQuery(allsongsuri, projection , selection, null, null);
        count = musiccursor.getCount();
        musiclist = (ListView) findViewById(R.id.PhoneMusicList);
        musiclist.setAdapter(new EfficientAdapter(getApplicationContext()));
        musiclist.setOnItemClickListener(musicgridlistener);
  }
  private OnItemClickListener musicgridlistener = new OnItemClickListener() {
        public void onItemClick(AdapterView parent, View v, int position,long id) {
              System.gc();
              music_column_index = musiccursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA);
              musiccursor.moveToPosition(position);
              filename = musiccursor.getString(music_column_index);
              aIntent = new Intent(v.getContext(), AudioFX.class);
              aIntent.getStringExtra(filename);
              startActivity(aIntent);
        }
      };
     class EfficientAdapter extends BaseAdapter {
      private Context mContext;
      public EfficientAdapter(Context c) {
          mContext = c;
      }
          public int getCount() {
                return count;
          }
          public Object getItem(int position) {
                return position;
          }
          public long getItemId(int position) {
                return position;
          }
          public View getView(int position, View convertView, ViewGroup parent) {
              System.gc();
              String id = null;
              TextView tv;
              if (convertView == null) {
              tv = new TextView(mContext.getApplicationContext());
              } else{
              tv = (TextView) convertView;
              }
              musiccursor.moveToPosition(position);
              music_column_index = musiccursor
              .getColumnIndexOrThrow(MediaStore.Audio.Media.TITLE);
              id = musiccursor.getString(music_column_index);
              tv.setText(id);
              tv.setTextSize(20);
              return tv;
              }}}

Answer 1

你只需要使用 DEFAULT_SORT_ORDER ，像这样：

String sortOrder = MediaStore.Audio.Media.DEFAULT_SORT_ORDER;
musiccursor = managedQuery(allsongsuri, projection , selection, null, sortOrder);

Answer 2

在 getView 方法中显示标题不会获得按字母顺序排列的列表。

为了按字母顺序排列列表，将所有音乐标题放入字符串数组或数组列表中手动按字母顺序排列它们，并将该字符串数组传递给 EfficientAdapters 构造函数并将其存储在本地并根据列表位置使用它们。

喜欢

 class EfficientAdapter extends BaseAdapter {
  private Context mContext;
  private String values[];
  public EfficientAdapter(Context c, String[] a) {
      mContext = c;
      values = a;
  }
      public int getCount() {
            return count;
      }
      public Object getItem(int position) {
            return position;
      }
      public long getItemId(int position) {
            return position;
      }
      public View getView(int position, View convertView, ViewGroup parent) {
          System.gc();
          String id = null;
          TextView tv;
          if (convertView == null) {
          tv = new TextView(mContext.getApplicationContext());
          } else{
          tv = (TextView) convertView;
          }
          id = values[position];

          tv.setText(id);
          tv.setTextSize(20);
          return tv;
          }}}

希望这有帮助.....