[移动开发]Android 下简单的 MP3 播放（代码分析）

本代码为教学材料，仅作学习使用，分析在注释里。

1.调用代码（RingDataAdapter）

public void togglePosition(int position,String curMusic) {
    if (expandPosition != position) {
        //此方法可以中途切换mp3播放 begin 
        MyMediaPlayer myMediaPlayer=MyMediaPlayer.getInstance();
        myMediaPlayer.setCurMusic(curMusic);
        myMediaPlayer.playMusic();
        notifyItemChanged(expandPosition);
        //此方法可以中途切换mp3播放 end
        expandPosition = position;
    } else {
        expandPosition = -1;
    }
    notifyItemChanged(position);
}

2.播放MP3核心代码（MyMediaPlayer）单例实现

package cn.fowit.xshow.utils;

import android.media.MediaPlayer;
import android.os.Handler;

public class {
    private MediaPlayer mediaPlayer;
    //放音频路径
    private String curMusic = "";
    private static volatile MyMediaPlayer instance = null;

    private MyMediaPlayer() { }

    public static MyMediaPlayer getInstance() {
        if (instance == null) {
            synchronized (MyMediaPlayer.class) {
                if (instance == null) {
                    instance = new MyMediaPlayer();

                }

            }

        }
        return instance;

    }


    //此方法可以中途切换音频
    public void playMusic(){
        try{
            if (mediaPlayer==null){
                mediaPlayer = new MediaPlayer();
                mediaPlayer.setDataSource(curMusic);
                mediaPlayer.prepare();
                mediaPlayer.start();
            }else if (mediaPlayer.isPlaying()){
                mediaPlayer.stop();
                new Handler().postDelayed(new Runnable(){
                    @Override
                    public void run() {
                        try{
                            mediaPlayer.reset();
                            mediaPlayer.setDataSource(curMusic);
                            mediaPlayer.prepare();
                            mediaPlayer.start();
                        }catch (Exception e){
                            curMusic = "";
                            e.printStackTrace();
                        }
                    }
                }, 1000);

            }else{
                mediaPlayer = new MediaPlayer();
                mediaPlayer.setDataSource(curMusic);
                mediaPlayer.prepare();
                mediaPlayer.start();
            }

        }catch (Exception e){
            curMusic = "";
        }
        mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mediaPlayer) {
                curMusic = "";
            }
        });
    }
    public void mediaPlayerStop(){
        //停止音乐播放
        if (mediaPlayer!=null&&mediaPlayer.isPlaying()) {
            mediaPlayer.stop();
        }
    }

    public String getCurMusic() {
        return curMusic;
    }

    public void setCurMusic(String curMusic) {
        this.curMusic = curMusic;
    }
}