Android开发之本地音乐播放器（简单粗暴版）

• 本程序为直接在Activity中计算并更新后台服务音乐播放进度，没有使用到广播

• 在学习广播之前，艰难的通过这个方法来实现了更新音乐播放进度，不推荐使用，不过感兴趣的可以研究一下。

• 大概的思路就是通过异步任务类来模拟耗时操作，然后计算出开始播放的时间与当前时间的差，然后跟音乐的总时间相比得到ProgressBar的进度，然后每一秒更新一次。

• 暂停时可以将暂停的时间加到开始时间上，实现无断点更新

• 效果图如下：
  

• 主函数代码：MusicActivity.java

public class MusicActivity extends AppCompatActivity {    private ListView lv;    private List lvList;    private List<Mp3Info> mp3InfoList;    private ImageButton bt1,bt2;    private ImageView iv1;    private TextView tv1,tv2;    private ProgressBar pb;    private Boolean flag;    private int location;    private long startTime;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_music);        lv= (ListView) findViewById(R.id.lv);        bt1= (ImageButton) findViewById(R.id.bt1);        bt2= (ImageButton) findViewById(R.id.bt2);        tv1= (TextView) findViewById(R.id.tv1);        tv2= (TextView) findViewById(R.id.tv2);        iv1= (ImageView) findViewById(R.id.iv1);        pb= (ProgressBar) findViewById(R.id.pb);        location=0;        flag=false;        LoadLvList();        ArrayAdapter aa=new ArrayAdapter(this,android.R.layout.simple_list_item_1,lvList);        lv.setAdapter(aa);        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {            @Override            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {                location=position;                setPlay(position);            }        });        bt1.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent=new Intent(MusicActivity.this, MyService.class);                intent.putExtra("tag",1);                startService(intent);                if(flag==true){                    bt1.setImageResource(R.mipmap.btn_pause);                    flag=false;                }else{                    bt1.setImageResource(R.mipmap.btn_play);                    flag=true;                }            }        });        bt2.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                location=location+1;                setPlay(location);            }        });    }    public void LoadLvList() {        mp3InfoList=new ArrayList<Mp3Info>();        mp3InfoList= MediaUtil.getMusicInfo(this);        lvList=new ArrayList();        for(int i=0;i<mp3InfoList.size();i++){            lvList.add(mp3InfoList.get(i).getTitle());        }    }    public void setPlay(int location){        Intent intent=new Intent(MusicActivity.this, MyService.class);        Mp3Info mp3Info=mp3InfoList.get(location);        intent.putExtra("tag",0);        intent.putExtra("url",mp3Info.getUrl());        intent.putExtra("id",mp3Info.getId());        intent.putExtra("title",mp3Info.getTitle());        intent.putExtra("artist",mp3Info.getArtist());        intent.putExtra("albumId",mp3Info.getAlbumId());        startService(intent);        tv1.setText(mp3Info.getTitle());        tv2.setText(mp3Info.getArtist());        Bitmap bitmap = MediaUtil.getArtwork(getBaseContext(), mp3Info.getId(),                mp3Info.getAlbumId(), true, false);        iv1.setImageBitmap(bitmap);        if(flag==false){            bt1.setImageResource(R.mipmap.btn_play);            flag=true;        }        int duration=(int)mp3Info.getDuration();        new MyProgress().execute(duration);    }    public class MyProgress extends AsyncTask<Integer,Integer,Integer> {        @Override        protected void onPreExecute() {            super.onPreExecute();            startTime=System.currentTimeMillis();            pb.setMax(100);            pb.setProgress(0);        }        @Override        protected Integer doInBackground(Integer... params) {            int i=0;            while(true){                try {                    Thread.sleep(1000);                } catch (InterruptedException e) {                    e.printStackTrace();                }if(flag==true) {                    Long currentTime = System.currentTimeMillis();                    int progress = (int) ((currentTime - startTime) * 100 / params[0]);                    Log.d("===progress", "" + progress);                    Log.d("===currentTime", "" + currentTime);                    Log.d("===startTime", "" + startTime);                    Log.d("===duration", "" + params[0]);                    if (progress <= 100) {                        publishProgress(progress);                    }                }else{                    startTime=startTime+1000;                    continue;                }                if(1000*i>=params[0]){                    break;                }                i++;            }            return 0;        }        @Override        protected void onProgressUpdate(Integer... values) {            Log.d("===","更新进度"+values[0]);            super.onProgressUpdate(values[0]);            pb.setMax(100);            pb.setProgress(values[0]);        }        @Override        protected void onPostExecute(Integer integer) {            Log.d("===","异步类执行完毕");            super.onPostExecute(integer);            setPlay(location);        }    }}

• service部分的代码：MyService.java

public class MyService extends Service {    private MediaPlayer mediaPlayer;    private NotificationManager nm;    private NotificationCompat.Builder builder;    private Notification nf;    public MyService() {    }    public class MyBind extends Binder {        public MyService getService() {            return MyService.this;        }    }    public void test() {        Log.d("====", "我是Service里的方法");        stopSelf();    }    @Override    public void onCreate() {        super.onCreate();        mediaPlayer = new MediaPlayer();        Log.d("====", "服务创建");    }    @Override    public int onStartCommand(Intent intent, int flags, int startId) {        Log.d("====", "服务启动--非绑定方式");        if(intent!=null){            int tag=intent.getIntExtra("tag",3);            switch (tag){                case 0:                    String url=intent.getStringExtra("url");                    String title=intent.getStringExtra("title");                    String artist=intent.getStringExtra("artist");                    long id=intent.getLongExtra("id",0);                    long albumId=intent.getLongExtra("albumId",0);                    try {                        if(mediaPlayer!=null){                            mediaPlayer.reset();                        }                        mediaPlayer.setDataSource(this, Uri.parse(url));                        mediaPlayer.prepare();                        mediaPlayer.setLooping(true);                        mediaPlayer.start();                        showNotification(title,artist,id,albumId);                    } catch (IOException e) {                        e.printStackTrace();                    }                    break;                case 1:                    if(mediaPlayer!=null){                        if(mediaPlayer.isPlaying()){                            mediaPlayer.pause();                        }else{                            mediaPlayer.start();                        }                    }                    break;                default:                    break;            }        }        return super.onStartCommand(intent, flags, startId);    }    private void showNotification(String title, String artist,long id,long albumId) {        nm= (NotificationManager) getSystemService(Activity.NOTIFICATION_SERVICE);        builder= new NotificationCompat.Builder(getBaseContext());        RemoteViews contentView=new RemoteViews(getPackageName(),R.layout.notification_music_layout);        contentView.setTextViewText(R.id.tv1,title);        contentView.setTextViewText(R.id.tv2,artist);        Bitmap bitmap = MediaUtil.getArtwork(this, id,                albumId, true, false);// 获取专辑位图对象，为大图        contentView.setImageViewBitmap(R.id.iv1,bitmap);        builder.setContent(contentView).setSmallIcon(R.mipmap.ic_launcher);        nf=builder.build();        nm.notify(0,nf);    }    @Override    public IBinder onBind(Intent intent) {        Log.d("====", "服务启动--绑定方式");        return new MyBind();    }    @Override    public boolean onUnbind(Intent intent) {        Log.d("====", "服务启动--绑定方式--解除绑定");        return super.onUnbind(intent);    }    @Override    public void onDestroy() {        super.onDestroy();        mediaPlayer.stop();        Log.d("====", "服务销毁");    }}

• 布局代码（用到的两个布局差不多）：

<RelativeLayout 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"    tools:context="com.example.ygd.jreduch10.MusicActivity">    <ListView        android:id="@+id/lv"        android:layout_above="@+id/pb"        android:layout_width="match_parent"        android:layout_height="match_parent"></ListView>    <ProgressBar        android:id="@+id/pb"        android:background="#FFFF"        style="?android:attr/progressBarStyleHorizontal"        android:layout_above="@+id/rl"        android:layout_width="match_parent"        android:layout_height="wrap_content" />    <RelativeLayout        android:id="@+id/rl"        android:background="#a19f9f"        android:layout_alignParentBottom="true"        android:layout_width="match_parent"        android:layout_height="wrap_content">        <ImageView            android:id="@+id/iv1"            android:src="@mipmap/ic_launcher"            android:layout_width="wrap_content"            android:layout_height="wrap_content" />        <TextView            android:layout_marginLeft="20dp"            android:id="@+id/tv1"            android:textSize="20sp"            android:text="HelloMusic"            android:textColor="#FFFF"            android:layout_toRightOf="@+id/iv1"            android:layout_width="wrap_content"            android:layout_height="wrap_content" />        <TextView            android:id="@+id/tv2"            android:layout_marginLeft="20dp"            android:textColor="#FFFF"            android:layout_toRightOf="@+id/iv1"            android:layout_below="@+id/tv1"            android:text="HelloSinger"            android:layout_width="wrap_content"            android:layout_height="wrap_content" />        <ImageButton            android:id="@+id/bt1"            android:layout_marginRight="20dp"            android:layout_toLeftOf="@+id/bt2"            android:src="@mipmap/btn_pause"            android:layout_width="wrap_content"            android:layout_height="wrap_content" />        <ImageButton            android:id="@+id/bt2"            android:layout_alignParentRight="true"            android:layout_marginRight="10dp"            android:src="@mipmap/btn_next"            android:layout_width="wrap_content"            android:layout_height="wrap_content" />    </RelativeLayout></RelativeLayout>