android服务之MP3播放(2)

该播放器将会直接从网络上获取资源进行播放，并提供进度条显示的功能

布局文件

---

布局文件中使用Seekbar组件来显示进度条

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

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

Activity

---

在Activity中需要做两件事情，第一：从消息队列中获取关于当前MP3的播放进度，通过播放进度修改SeekBar的属性。第二：因为可以通过进度条来控制播放进度，所以获取进度条的相关信息来控制播放进度。

package xidian.dy.com.chujia;

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

public class MainActivity extends AppCompatActivity {
    IMusic music;
    static SeekBar sb;
    static Handler handler = new Handler(){
        public void handleMessage(Message msg){
            Bundle bundle = msg.getData();
            sb.setMax(bundle.getInt("duration"));
            sb.setProgress(bundle.getInt("current"));
        }
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Intent intent = new Intent(this, MusicService.class);
        startService(intent);
        bindService(intent, new MyConnection(), BIND_AUTO_CREATE);
        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) {
                music.seekTo(seekBar.getProgress());
            }
        });
    }

    public void play(View v){
        music.play();
    }

    public void pause(View v){
        music.pause();
    }

    public void continuePlay(View v){
        music.continuePlay();
    }

    class MyConnection implements ServiceConnection{

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

        @Override
        public void onServiceDisconnected(ComponentName name) {

        }
    }
}

Service

---

在Service中需要过去当前的播放信息，并将其写在消息队列中传递给Activity线程。并且向外提供一个提供改变当前播放进度接口

package xidian.dy.com.chujia;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Binder;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Message;
import android.support.annotation.Nullable;
import android.util.Log;

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

/**
 * Created by dy on 2016/7/29.
 */
public class MusicService extends Service {
    MediaPlayer player;
    Timer timer;

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

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return new MyBinder();
    }

    public void continuePlay(){
        player.start();
    }

    public void pause(){
        player.pause();
    }

    public void play(){
        player.reset();
        try {
            player.setDataSource("http://123.206.68.138/mg.mp3");
            player.prepareAsync();
            player.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                @Override
                public void onPrepared(MediaPlayer mp) {
                    mp.start();
                    timer.schedule(new TimerTask() {
                        @Override
                        public void run() {
                            Bundle bundle = new Bundle();
                            bundle.putInt("duration", player.getDuration());
                            bundle.putInt("current", player.getCurrentPosition());
                            Message msg = MainActivity.handler.obtainMessage();
                            msg.setData(bundle);
                            MainActivity.handler.sendMessage(msg);
                            Log.i("duration", String.valueOf(player.getDuration()));
                        }
                    }, 5, 500);
                }
            });
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

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

    class MyBinder extends Binder implements IMusic{
        @Override
        public void play() {
            MusicService.this.play();
        }

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

        public void seekTo(int msc){
            player.seekTo(msc);
        }
        @Override
        public void continuePlay() {
            MusicService.this.continuePlay();
        }
    }
}

接口

---

该接口是连接service和Activity的

package xidian.dy.com.chujia;

/**
 * Created by dy on 2016/7/29.
 */
public interface IMusic {
    void play();
    void pause();
    void continuePlay();
    void seekTo(int msc);
}

清单文件

---

在清单文件中需要开启网络权限

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="xidian.dy.com.chujia">
<uses-permission android:name="android.permission.INTERNET"/>
<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity
        android:name=".MainActivity"
        android:label="主界面">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <service android:name=".MusicService"/>
</application>
</manifest>