android音乐播放器，可进度条调节

1、将服务中的方法抽取问接口
2、添加Timer定时器，向MainActivity发送当前音乐播放进度，
int duration = player.getDuration();
int currentposition = player.getCurrentPosition();
3、主线程根据接收到的信息，更新UI
4、为SeekBar设置监听setOnSeekBarChangeListener，在service中添加seekto方法（接口中也要添加），在seekto方法中 player.seekto();
在onStopTrackingTouch()方法中调用在Service中的seekto()方法

MainActivity.java

package com.itheima.musicplayer;

import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.SeekBar;

public class MainActivity extends AppCompatActivity {

    static Handler handler = new Handler(){

        int currentposition;

        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            Bundle bundle = msg.getData();
            int duration = bundle.getInt("duration");
            currentposition = bundle.getInt("currentposition");
            sb.setMax(duration);
            sb.setProgress(currentposition);
        }
    };

    MusicInterface mi;
    private static SeekBar sb;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        sb= (SeekBar) findViewById(R.id.sb);
        sb.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {

            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                int progress = seekBar.getProgress();
                mi.seekto(progress);
            }
        });
        Intent intent = new Intent(this,PlayerService.class);
        MyServiceConn cnn = new MyServiceConn();

        //混合启动服务
        startService(intent);
        bindService(intent,cnn,BIND_AUTO_CREATE);

    }

    class MyServiceConn implements ServiceConnection{

        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            mi = (MusicInterface) service;
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {

        }
    }
    public void play(View v){
        System.out.println("sssss");
        mi.play();
    }
    public void pause(View v){
        mi.pause();
    }
    public void continueplay(View v){
        mi.continueplay();
    }
}

PlayerService.java

package com.itheima.musicplayer;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Binder;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.view.View;

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

public class PlayerService extends Service {
    MediaPlayer player;
    Timer timer;

    public PlayerService() {
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
       // throw new UnsupportedOperationException("Not yet implemented");
        return new MusicController();
    }

    @Override
    public void onCreate() {
        super.onCreate();
        player=new MediaPlayer();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        player.stop();
        player.release();
        player = null;
        if (timer!=null){
            timer.cancel();
            timer=null;
        }
    }

    class MusicController extends Binder implements MusicInterface{
        public void play(){
            PlayerService.this.play();
        }
        public void pause(){
            PlayerService.this.pause();
        }

        @Override
        public void continueplay() {
            PlayerService.this.continueplay();
        }

        @Override
        public void seekto(int currentposition) {
            PlayerService.this.seekto(currentposition);
        }
    }


    public void seekto(int currentposition){
        player.seekTo(currentposition);
    }


    public void play() {
        System.out.println("播放音乐");

        player.reset();
        try {
//            player.setDataSource("sdcard/heibaizhao.mp3");
//            player.prepare();//准备
//            player.start();
            player.setDataSource("http://10.0.3.2:8080/heibaizhao.mp3");
            System.out.println("连接成功");
            player.prepareAsync();
            player.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                @Override
                public void onPrepared(MediaPlayer mp) {
                    System.out.println("加载成功");
                    player.start();
                    addTimer();
                }
            });

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public void continueplay(){
        player.start();
    }

    public void pause() {
        System.out.println("暂停");
        player.pause();
    }
    public void addTimer(){

        if(timer==null){

            timer = new Timer();
            timer.schedule(new TimerTask() {
              @Override
                public void run() {
                    int duration = player.getDuration();
                    int currentposition = player.getCurrentPosition();

                    Message msg = MainActivity.handler.obtainMessage();

                    Bundle bundle = new Bundle();
                    bundle.putInt("duration", duration);
                    bundle.putInt("currentposition", currentposition);

                     msg.setData(bundle);

                    MainActivity.handler.sendMessage(msg);


                }
            }, 5, 500);
        }
    }
}

musicInterface.java

package com.itheima.musicplayer;

/**
 * Created by Administrator on 2015/12/23.
 */
public interface MusicInterface {
    void play();
    void pause();
    void continueplay();
    void seekto(int currentposition);
}

布局文件activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/play"
        android:onClick="play"
        android:text="开始播放"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/pause"
        android:onClick="pause"
        android:text="暂停播放"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/continueplay"
        android:onClick="continueplay"
        android:text="继续播放"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <SeekBar
        android:id="@+id/sb"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>