Question

我创建了一个音乐播放器，它从一个androidhive教程中读取SD卡中的mp3文件我想从原始文件夹中读取10首歌曲。

为此，我创建了这段代码但它不起作用。

请帮忙。

package com.example.mediaplayer;

import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
import java.util.HashMap;

public class SongsManager {
    // SDCard Path
    final String MEDIA_PATH = new String("/sdcard/");
    private ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();

    // Constructor
    public SongsManager(){

    }

    /**
     * Function to read all mp3 files from sdcard
     * and store the details in ArrayList
     * */
    public ArrayList<HashMap<String, String>> getPlayList(){
        File home = new File(MEDIA_PATH);

        if (home.listFiles(new FileExtensionFilter()).length > 0) {
            for (File file : home.listFiles(new FileExtensionFilter())) {
                HashMap<String, String> song = new HashMap<String, String>();
                song.put("songTitle", file.getName().substring(0, (file.getName().length() - 4)));
                song.put("songPath", file.getPath());

                // Adding each song to SongList
                songsList.add(song);
            }
        }
        // return songs list array
        return songsList;
    }

    /**
     * Class to filter files which are having .mp3 extension
     * */
    class FileExtensionFilter implements FilenameFilter {
        public boolean accept(File dir, String name) {
            return (name.endsWith(".mp3") || name.endsWith(".MP3"));
        }
    }
}

Answer 1

这是一个支持原始文件的媒体播放器的丑陋概念验证：

public class RawMediaPlayer {

    private Context mContext = null;
    private int mPosition = 0;
    private ArrayList<Integer> mRawList = null;

    public static RawMediaPlayer create(Context context, ArrayList<Integer> rawList) {
        return new RawMediaPlayer(context, rawList);
    }

    private RawMediaPlayer(Context context, ArrayList<Integer> rawList) {

        mContext = context;
        mRawList = rawList;

        MediaPlayer mediaPlayer = new MediaPlayer();
        mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mediaPlayer) {

                mPosition++;

                if (mRawList.size() <= mPosition)
                    return;

                loadRawFile(mediaPlayer, mRawList.get(mPosition));
            }
        });

        loadRawFile(mediaPlayer, mRawList.get(0));
    }


    private void loadRawFile(MediaPlayer mediaPlayer, int resId) {
        try {
            AssetFileDescriptor afd = mContext.getResources().openRawResourceFd(resId);

            if (afd == null)
                return;

            mediaPlayer.reset();
            mediaPlayer.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
            mediaPlayer.prepare();
            mediaPlayer.start();

            afd.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

您可以这样使用：

final ArrayList<Integer> list = new ArrayList<Integer>();
list.add(R.raw.sample_1);
list.add(R.raw.sample_2);
list.add(R.raw.sample_3);

RawMediaPlayer.create(context, list);

从原始文件夹

1 个答案: