音乐播放器之简单播放（MediaPlayer、Service、BroadcastRecevier的结合用法）

(小白一个，代码仅供参考)

做一个音乐播放器，就要考虑到实现后台音乐的播放，进度条的实现，播放时间和音频时间的实现。 在Android中，BroadcastRecevier Service 和 MediaPlayer就可以实现下面的操作。

先看Activity

package com.example.bear.test;import android.app.Activity;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.content.IntentFilter;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.ImageButton;import android.widget.SeekBar;import android.widget.TextView;public class MainActivity extends Activity implements View.OnClickListener{    //为日志工具设置标签    private static String TAG = "MusicService";    protected boolean isplay = false;    private static final int PLAY = 1;    private static final int PAUSE = 2;    private static final int STOP = 3;// 停止    private static final int PROGRESS_CHANGE = 4;    private static final int STATE_PLAY = 1;// 播放状态设为1    private static final int STATE_PAUSE = 2;// 播放状态设为2    private SeekBar mSeekBar;    private ImageButton btnStart;    private Button btnStop;    private int flag;// 标记    private TextView startTime, stopTime;    private MyBroadcastReceiver myBroadcastReceiver = new MyBroadcastReceiver();    /**     * Called when the activity is first created.     */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initlizeViews();    }    @Override    protected void onResume() {        super.onResume();        //注册广播接收器        IntentFilter filter = new IntentFilter();        //设置接收广播的类型，这里要和Service里设置的类型匹配，还可以在AndroidManifest.xml文件中注册        filter.addAction("com.bear.app");        this.registerReceiver(myBroadcastReceiver, filter);        mSeekBar.setProgress(0);        play();    }    @Override    protected void onStop() {        super.onStop();        this.unregisterReceiver(myBroadcastReceiver);    }    @Override    protected void onDestroy() {        super.onDestroy();        stop();        this.unregisterReceiver(myBroadcastReceiver);        finish();    }    private void initlizeViews() {        btnStart = (ImageButton) findViewById(R.id.startMusic);        btnStop = (Button) findViewById(R.id.stopMusic);        mSeekBar = (SeekBar) findViewById(R.id.seekbar1);        startTime = (TextView) findViewById(R.id.startTime);        stopTime = (TextView) findViewById(R.id.stopTime);        //绑定点击监听        btnStart.setOnClickListener(this);        btnStop.setOnClickListener(this);        ShowSeekBar();    }    @Override    public void onClick(View v) {        //显示指定  intent所指的对象是个   service        if(v.getId() == R.id.startMusic){            switch (flag) {                case STATE_PLAY:                    //开始服务                    pause();                    break;                case STATE_PAUSE:                    //停止服务                    play();                    break;            }        }else {            stop();        }    }    private void stop() {        Intent intent = new Intent();        intent.setAction("com.app.media.MUSIC_SERVICE");        intent.setPackage(getPackageName());        stopService(intent);    }    private void ShowSeekBar() {        mSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {            @Override            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {                if (fromUser) {                    Intent intent = new Intent();                    intent.setAction("com.app.media.MUSIC_SERVICE");                    intent.setPackage(getPackageName());                    intent.putExtra("op", PROGRESS_CHANGE);                    intent.putExtra("progress", progress);                    startService(intent);                }            }            @Override            public void onStartTrackingTouch(SeekBar seekBar) {            }            @Override            public void onStopTrackingTouch(SeekBar seekBar) {            }        });    }    /**     * 播放时间转换     */    public String toTime(int time) {        time /= 1000;        int minute = time / 60;        int second = time % 60;        minute %= 60;        return String.format("%02d:%02d", minute, second);    }    /**     * 在播放布局里先把播放按钮先删除并用background设置为透明。然后在代码添加按钮     */    public void play() {        flag = PLAY;        btnStart.setImageResource(R.drawable.player_btn_player_pause);        Intent intent = new Intent();        intent.setAction("com.app.media.MUSIC_SERVICE");        intent.setPackage(getPackageName());        intent.putExtra("op", PLAY);// 向服务传递数据        startService(intent);    }    /**     * 暂停     */    public void pause() {        flag = PAUSE;        btnStart.setImageResource(R.drawable.player_btn_player_play);        Intent intent = new Intent();        intent.setAction("com.app.media.MUSIC_SERVICE");        intent.setPackage(getPackageName());        intent.putExtra("op", PAUSE);        startService(intent);    }    class MyBroadcastReceiver extends BroadcastReceiver {        @Override        public void onReceive(Context context, Intent intent) {            int duration = intent.getIntExtra("duration",-1);            int progress = intent.getIntExtra("seekBarProgress",-1);            if(duration != -1){                mSeekBar.setMax(duration);                stopTime.setText(toTime(duration));            }            if(progress != -1){                mSeekBar.setProgress(progress);                startTime.setText(toTime(progress));            }        }    }}

在MainActivity中，我把play、pause、和改变进度条的事件传到service中，然后在service中实现；而且在service中把音频的总长度和当前播放长度传到主线程中，从而实现了以上功能

看Service

package com.example.bear.test;import android.app.Service;import android.content.Intent;import android.media.MediaPlayer;import android.os.IBinder;import android.util.Log;/** * Created by Bear on 2015/8/7. */public class MusicService extends Service{    //为日志工具设置标签    private static String TAG = "MusicService";    //定义音乐播放器变量    private MediaPlayer mPlayer;    private final int mSeekBarLen = 2000;    private SeekBarThread seekBarThread;    private static final int MUSIC_PLAY = 1;    private static final int MUSIC_PAUSE = 2;    private static final int MUSIC_STOP = 3;    private static final int PROGRESS_CHANGE = 4;    //该服务不存在需要被创建时被调用，不管startService()还是bindService()都会启动时调用该方法    @Override    public void onCreate() {        mPlayer = MediaPlayer.create(getApplicationContext(), R.raw.music);        //设置可以重复播放        mPlayer.setLooping(true);        super.onCreate();    }    @Override    public int onStartCommand(Intent intent, int flags, int startId) {        startBarThread();        int op = intent.getIntExtra("op",-1);        if(op != -1) {            switch (op) {                case MUSIC_PLAY:                    if (!mPlayer.isPlaying()) {                        mPlayer.start();                    }                    break;                case MUSIC_PAUSE:                    if (mPlayer.isPlaying()) {                        mPlayer.pause();                    }                    break;                case PROGRESS_CHANGE:                    int currentTime = intent.getExtras().getInt("progress");                    mPlayer.seekTo(currentTime);                    break;            }        }        return super.onStartCommand(intent, flags, startId);    }    @Override    public void onDestroy() {        mPlayer.stop();        if (seekBarThread != null) {            seekBarThread.off();        }        super.onDestroy();    }    @Override    public IBinder onBind(Intent intent) {        return null;    }    private void startBarThread() {        if (seekBarThread != null) {            seekBarThread.off();        }        seekBarThread = new SeekBarThread();        seekBarThread.start();    }    class SeekBarThread extends Thread {        boolean flag = true;        int duration = 1;        int seekBarProgress = 0;        int position = 0;        public SeekBarThread() {};        public void off() {            flag = false;        }        public void run() {            flag = true;            if(mPlayer!=null) {                duration = mPlayer.getDuration();            }            seekBarProgress = 0;            position = 0;            while (flag) {                if(mPlayer!=null) {                    position = mPlayer.getCurrentPosition();                }                seekBarProgress =position;//                Log.e("TEST",position+"");//                Log.e("TEST",seekBarProgress+"");//                Log.e("TEST",duration+"");                Intent intent = new Intent();                intent.putExtra("seekBarProgress",seekBarProgress);                intent.putExtra("duration",duration);                //设置广播的类型                intent.setAction("com.bear.app");                sendBroadcast(intent);                try {                    sleep(1000);                } catch (InterruptedException e) {                    e.printStackTrace();                }            }        }// while    }}

在service中，实现一个新的线程来实现音频时间的处理，从而减少主线程的时间。我们都知道，主线程时间不能够长，长时间的操作应该放到其他线程中。

注意：感觉说了这么多，还是没什么用，看代码才是重点。

---