将 ArrayList<Object> 传递回 main Activity (Android)

Passing ArrayList<Object> back to main Activity (Android)

我有一个 ArrayList< Object>，其中 Object 是我创建的 class 的一个实例。我想将这个新数组列表传递回主 activity 以将其放入导航抽屉项目中。

如何将 ArrayList 从 activity 传回主对象？

我试过 bundle.getParcelableArrayList 但是它告诉我 "Inferred type Object for type parameter T is not within its bounds, should implement android.os.parcelable"

这是我的代码：

public void createPlaylist(String playlistName, ArrayList<Song> newPlaylistSongsArray) {
    Intent returnIntent = new Intent();
    Bundle b = new Bundle();
    b.putParcelableArrayList("array", (ArrayList<? extends Parcelable>) newPlaylistSongsArray);
    returnIntent.putExtra("playListName", playlistName);
    returnIntent.putExtra("array", newPlaylistSongsArray);
    setResult(Activity.RESULT_OK,returnIntent);
    finish();
}

并且：

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 1) {
        if (resultCode == Activity.RESULT_OK){
            String newPlaylistName = data.getStringExtra("playListName");
            Bundle b = getIntent().getExtras();
            final ArrayList<Song> newPlaylist = b.getParcelableArrayList("array");
            Toast.makeText(MP3Player.this, "New Playlist Created", Toast.LENGTH_LONG).show();
        }
        if (resultCode == Activity.RESULT_CANCELED) {
            Toast.makeText(MP3Player.this, "Shit went wrong yo!", Toast.LENGTH_LONG).show();
        }
    }
}

为了最简单的方法，您的歌曲 class 需要实现 Serializable。

Bundle bundle = new Bundle();
bundle.putSerializable("newPlaylist", newPlaylist);
intent.putExtras(bundle);

其他 activity:

Intent intent = this.getIntent();
Bundle bundle = intent.getExtras();

ArrayList<Song> newPlaylist=
               (ArrayList<Song>)bundle.getSerializable("newPlaylist");