android97 播放音频 有进度条控制

package com.itheima.musicplayer;

import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.view.Menu;
import android.view.View;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;

public class MainActivity extends Activity {

    static Handler handler = new Handler(){//handler是谷歌说明的定义成静态的，
        public void handleMessage(android.os.Message msg) {
            Bundle bundle = msg.getData();
            int duration = bundle.getInt("duration");
            int currentPostition = bundle.getInt("currentPosition");
            //刷新进度条的进度，设置SeekBar的Max和Progress就能够时时更新SeekBar的长度，
            sb.setMax(duration);
            sb.setProgress(currentPostition);
        }
    };
    
    MusicInterface mi;
    private MyserviceConn conn;
    private Intent intent;
    private static SeekBar sb;//属性在对象生成的时候才有，所以在静态代码中要变成静态。
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sb = (SeekBar) findViewById(R.id.sb);
        sb.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {//SeekBar进度改变事件
            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {//手指抬起
                //拖动SeekBar的进度改变音乐播放进度
                int progress = seekBar.getProgress();
                //改变播放进度
                mi.seekTo(progress);
            }
            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {//手指按下
            }
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress,
                    boolean fromUser) {//手指滑动
            }
        });
        intent = new Intent(this, MusicService.class);
        startService(intent);
        conn = new MyserviceConn();
        bindService(intent, conn, BIND_AUTO_CREATE);
    }

    class MyserviceConn implements ServiceConnection{
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            mi = (MusicInterface) service;//中间人
        }
        @Override
        public void onServiceDisconnected(ComponentName name) {
        }
    }
    
    public void play(View v){
        mi.play();
    }
    public void continuePlay(View v){
        mi.continuePlay();
    }
    public void pause(View v){
        mi.pause();
    }
    public void exit(View v){
        unbindService(conn);  //解绑
        stopService(intent);  //停止
    }

}
//清单文件：<service android:name="com.itheima.musicplayer.MusicService"></service>
/*<SeekBar 
android:id="@+id/sb"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>   音乐播放器的进度条，可以拖动改变音乐的播放进度，不同于processBar不可以拖动*/ 

package com.itheima.musicplayer;

public interface MusicInterface {

    void play();
    void pause();
    void continuePlay();
    void seekTo(int progress);
}

package com.itheima.musicplayer;

import java.io.IOException;
import java.util.Timer;
import java.util.TimerTask;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Binder;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Message;

public class MusicService extends Service {

    MediaPlayer player;//播放音乐API
    private Timer timer;
    @Override
    public IBinder onBind(Intent intent) {
        return new MusicController();
    }

    class MusicController extends Binder implements MusicInterface{

        @Override
        public void play() {
            MusicService.this.play();
        }

        @Override
        public void pause() {
            MusicService.this.pause();
        }

        @Override
        public void continuePlay() {
            MusicService.this.continuePlay();
        }

        @Override
        public void seekTo(int progress) {
            MusicService.this.seekTo(progress);
        }
    }
    
    @Override
    public void onCreate() {
        super.onCreate();
        player = new MediaPlayer();
    }
    
    @Override
    public void onDestroy() {
        super.onDestroy();
        //停止播放
        player.stop();
        //释放占用的资源，此时player对象已经废掉了，但是player对象还在。
        player.release();
        player = null;
        if(timer != null){
            timer.cancel();
            timer = null;
        }
    }
    
    //播放音乐
    public void play(){
        //重置
        player.reset();
        try {
            //加载多媒体文件
            player.setDataSource("sdcard/zxmzf.mp3");//播放本地音频可以同步准备，调用主线程的player.prepare()方法和start()方法，因为主线程知道prepare()好了之后再start()
//            player.setDataSource("http://192.168.13.119:8080/bzj.mp3");  //播放网络音频是一个耗时操作必须要开启子线城异步准备调用player.prepareAsync()方法，这个方法默认就是开启子线城，不能直接调用主线程的start()方法因为主线程不知道子线城什么时候准备完毕，因此要在主线程做监听setOnPreparedListener()，当子线城准备完了之后主线程监听到了之后主线程才能start()
//            player.prepare();  因为调用了硬件所以要做准备
            player.prepareAsync();   //异步准备，开启子线程加载资源
//            player.start();
            player.setOnPreparedListener(new OnPreparedListener() {//准备监听
                //prepare()方法准备完毕时，此方法调用
                @Override
                public void onPrepared(MediaPlayer mp) {
                    player.start();
                    addTimer();
                }
            });
        } catch (Exception e) {
            e.printStackTrace();
        } 
    }
    
    //继续播放
    public void continuePlay(){
        player.start();
    }
    
    //暂停播放
    public void pause(){
        player.pause();
    }
    
    public void seekTo(int progress){
        player.seekTo(progress);
    }
    public void addTimer(){
        if(timer == null){
            timer = new Timer();//timer就是开启子线程执行任务，与纯粹的子线城不同的是可以控制子线城执行的时间，
            timer.schedule(new TimerTask() {
                
                @Override
                public void run() {
                    //获取歌曲总时长
                    int duration = player.getDuration();
                    //获取歌曲当前播放进度
                    int currentPosition= player.getCurrentPosition();
                    Message msg = MainActivity.handler.obtainMessage();
                    //把进度封装至消息对象中
                    Bundle bundle = new Bundle();
                    bundle.putInt("duration", duration);
                    bundle.putInt("currentPosition", currentPosition);
                    msg.setData(bundle);
                    MainActivity.handler.sendMessage(msg);
                }
                //开始计时任务后的5毫秒后第一次执行run方法，以后每500毫秒执行一次
            }, 5, 500);
        }
    }
}