音乐播放器

1，实例AndroidManifest.xml文件配置Service

<application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.example.musicproject.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <service android:name=".MusicService">        </service>    </application>

2，MainActivity.java

package com.example.musicproject;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.view.View.OnClickListener;import android.widget.ImageButton;import android.widget.TextView;public class MainActivity extends Activity implements OnClickListener{    // 获取界面中显示歌曲标题、作者文本框    TextView title, author;    // 播放/暂停、停止按钮    ImageButton play, stop;    ActivityReceiver activityReceiver;    public static final String CTL_ACTION =         "bzu.action.CTL_ACTION";    public static final String UPDATE_ACTION =        "bzu.action.UPDATE_ACTION";    // 定义音乐的播放状态，1代表没有播放；2代表正在播放；3代表暂停    int status = 1;    String[] titleStrs = new String[] { "七里香", "爱在西元前", "夜的第七章" };    String[] authorStrs = new String[] { "周杰伦", "许嵩", "林俊杰" };    @Override    public void onCreate(Bundle savedInstanceState)    {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();        activityReceiver = new ActivityReceiver();        // 注册BroadcastReceiver        // 创建IntentFilter        IntentFilter filter = new IntentFilter();        // 指定BroadcastReceiver监听的Action        filter.addAction(UPDATE_ACTION);        registerReceiver(activityReceiver, filter);        // 启动后台Service        Intent intent = new Intent(this, MusicService.class);        startService(intent);    }    private void initView(){        // 获取程序界面界面中的两个按钮        play = (ImageButton) this.findViewById(R.id.play);        stop = (ImageButton) this.findViewById(R.id.stop);        title = (TextView) findViewById(R.id.title);        author = (TextView) findViewById(R.id.author);        // 为两个按钮的单击事件添加监听器        play.setOnClickListener(this);        stop.setOnClickListener(this);      }    // 自定义的BroadcastReceiver，负责监听从Service传回来的广播    public class ActivityReceiver extends BroadcastReceiver    {        @Override        public void onReceive(Context context, Intent intent)        {            // 获取Intent中的update消息，update代表播放状态            int update = intent.getIntExtra("update", -1);            // 获取Intent中的current消息，current代表当前正在播放的歌曲            int current = intent.getIntExtra("current", -1);            if (current >= 0){//设置信息                title.setText(titleStrs[current]);                author.setText(authorStrs[current]);            }            switch (update)            {                // 进入播放状态                case 1:                    play.setImageResource(R.drawable.play);                    status = 1;                    break;                // 控制系统进入暂停状态                case 2:                    // 播放状态下设置使用暂停图标                    play.setImageResource(R.drawable.pause);                    // 设置当前状态                    status = 2;                    break;                // 暂停状态下设置使用播放图标                case 3:                    play.setImageResource(R.drawable.play);                    // 设置当前状态                    status = 3;                    break;            }        }    }    @Override    public void onClick(View source)    {        // 创建Intent        Intent intent = new Intent("bzu.action.CTL_ACTION");        switch (source.getId())        {            // 按下播放/暂停按钮            case R.id.play:                intent.putExtra("control", 1);                break;            // 按下停止按钮            case R.id.stop:                intent.putExtra("control", 2);                break;        }        // 发送广播，将被Service组件中的BroadcastReceiver接收到        sendBroadcast(intent);    }}

 

3,MusicService.java

/**

 *

 */

package com.example.musicproject;import java.io.IOException;import android.app.Service;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.content.IntentFilter;import android.content.res.AssetFileDescriptor;import android.content.res.AssetManager;import android.media.MediaPlayer;import android.media.MediaPlayer.OnCompletionListener;import android.os.IBinder;public class MusicService extends Service{    //广播    MyReceiver serviceReceiver;    AssetManager am;    String[] musics = new String[] { "pfzl.mp3", "xws.mp3",        "zzlfz.mp3" };    MediaPlayer mPlayer;    // 当前的状态,1 代表没有播放 ；2代表 正在播放；3代表暂停    int status = 1;    // 记录当前正在播放的音乐    int current = 0;    @Override    public IBinder onBind(Intent intent)    {        return null;    }    @Override    public void onCreate()    {        am = getAssets();        // 创建BroadcastReceiver        serviceReceiver = new MyReceiver();        // 创建IntentFilter        IntentFilter filter = new IntentFilter();        filter.addAction(MainActivity.CTL_ACTION);        registerReceiver(serviceReceiver, filter);        // 创建MediaPlayer        mPlayer = new MediaPlayer();        // 为MediaPlayer播放完成事件绑定监听器        mPlayer.setOnCompletionListener(new OnCompletionListener() //①        {            @Override            public void onCompletion(MediaPlayer mp)            {                current++;                if (current >= 3)                {                    current = 0;                }                // 发送广播通知Activity更改文本框                Intent sendIntent = new Intent(MainActivity.UPDATE_ACTION);                sendIntent.putExtra("current", current);                // 发送广播 ，将被Activity组件中的BroadcastReceiver接收到                sendBroadcast(sendIntent);                // 准备、并播放音乐                prepareAndPlay(musics[current]);            }        });        super.onCreate();    }    public class MyReceiver extends BroadcastReceiver    {        @Override        public void onReceive(final Context context, Intent intent)        {            //接收发送来的广播数据            int control = intent.getIntExtra("control", -1);            switch (control)            {                // 播放或暂停,判断上一次的状态                case 1:                    // 原来处于没有播放状态                    if (status == 1)                    {                        // 准备、并播放音乐                        prepareAndPlay(musics[current]);                        status = 2;                    }                    // 原来处于播放状态                    else if (status == 2)                    {                        // 暂停                        mPlayer.pause();                        // 改变为暂停状态                        status = 3;                    }                    // 原来处于暂停状态                    else if (status == 3)                    {                        // 播放                        mPlayer.start();                        // 改变状态                        status = 2;                    }                    break;                // 停止声音                case 2:                    // 如果原来正在播放或暂停                    if (status == 2 || status == 3)                    {                        // 停止播放                        mPlayer.stop();                        status = 1;                    }            }            // 发送广播通知Activity更改图标、文本框            Intent sendIntent = new Intent(MainActivity.UPDATE_ACTION);            sendIntent.putExtra("update", status);            sendIntent.putExtra("current", current);            // 发送广播 ，将被Activity组件中的BroadcastReceiver接收到            sendBroadcast(sendIntent);        }    }    private void prepareAndPlay(String music)    {        try        {            // 打开指定音乐文件            AssetFileDescriptor afd = am.openFd(music);            mPlayer.reset();            // 使用MediaPlayer加载指定的声音文件。            mPlayer.setDataSource(afd.getFileDescriptor(),                afd.getStartOffset(), afd.getLength());            // 准备声音            mPlayer.prepare();            mPlayer.start();        }        catch (IOException e)        {            e.printStackTrace();        }    }}