Android0910<十五>（简单的音乐播放器）

MediaPlayer

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.administrator.musicplayer" >
<uses-permission android:name="android.permission.READ_CONTACTS"></uses-permission>
<application
android:allowBackup="true"
android:icon="@mipmap/mediaplayer"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".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=".Service.MusicService"></service>
</application>

</manifest>

activity_main.xml

<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" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
android:background="@mipmap/background">

<ListView
android:id="@+id/listview_music"
android:layout_width="match_parent"
android:layout_height="match_parent"></ListView>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_alignParentBottom="true"
android:background="#00ffffff">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:orientation="horizontal"
android:weightSum="7">
<Button
android:id="@+id/btn_play"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="@drawable/btn_play"/>
</LinearLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_alignParentRight="true">
<TextView
android:id="@+id/text_timenow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="00:00"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="/"/>
<TextView
android:id="@+id/text_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="00:00 "/>
</LinearLayout>
</RelativeLayout>

<SeekBar
android:id="@+id/seekbar_music"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
</RelativeLayout>

activity_music.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/music_img"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/text_author"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="---"/>
<TextView
android:id="@+id/text_music"
android:layout_width="wrap_content"
android:layout_height="wrap_content"

/>
</LinearLayout>

MyMusicAdaper.java

public class MyMusicAdapter extends BaseAdapter{
private LayoutInflater mInflater;
private File[] musics;

public MyMusicAdapter(LayoutInflater mInflater, File[] musics) {
this.mInflater = mInflater;
this.musics = musics;
}

@Override
public int getCount() {
return musics.length;
}

@Override
public Object getItem(int position) {
return position;
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder vh=null;
if (vh==null){
vh=new ViewHolder();
convertView=mInflater.inflate(R.layout.activity_music,null);
vh.textMusic= (TextView) convertView.findViewById(R.id.text_music);
vh.img= (ImageView) convertView.findViewById(R.id.music_img);
vh.tvAuthor= (TextView) convertView.findViewById(R.id.text_author);
convertView.setTag(vh);
}
vh= (ViewHolder) convertView.getTag();
vh.textMusic.setText(musics[position].getName());
//MediaMetadataRetriever类提供了一个统一的接口用于从一个输入媒体文件中取得帧和元数据
MediaMetadataRetriever mediaMetadataRetriever=new MediaMetadataRetriever();
//setDataSource()方法获取数据源
mediaMetadataRetriever.setDataSource(musics[position].getAbsolutePath());
//用实例对象调用extractMetadata()方法获得想要的数据信息类型，
// 传参数为特定的键码，如：METADATA_KEY_ARTIST是获得数据中艺术家的信息。
String author=mediaMetadataRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_ARTIST);
if (author!=null){
vh.tvAuthor.setText(author);
}else{
vh.tvAuthor.setText("<未知>");
}
//getEmbeddedPicture()方法发现可选的图形或相册/封面与相关的数据源的艺术。如果有多张图片，返回其中的任何一个。
byte[] image=mediaMetadataRetriever.getEmbeddedPicture();
if (image!=null){
//Bitmap是Android系统中的图像处理的最重要类之一。用它可以获取图像文件信息
//BitmapFactory是从各种源创建位图对象，包括文件、数据流和字节数组。
//通过decodeByteArray()方法从指定的字节数组中解码一个不可变的位图，返回一个Bitmap类型的值
//data 第一个参数image是压缩图像数据的字节数组，
// offset第二个参数是偏移数据，解码器应该开始解析的地方
// length第三个参数是字节数，开始在偏移辆=量分析
//opts第四个参数是控制采样和图像是否应该完全解码的选项，或者仅仅是大小返回
Bitmap bitmap= BitmapFactory.decodeByteArray(image,0,image.length);
vh.img.setImageBitmap(bitmap);
}else{
vh.img.setImageResource(R.mipmap.mediaplayer);
}

return convertView;
}
class ViewHolder{
TextView textMusic;
ImageView img;
TextView tvAuthor;
}
}

MyMusicService.java

public class MusicService extends Service{
private MediaPlayer player;
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
int type=intent.getIntExtra("type", Config.START_NEW_MUSIC);
Log.d("TYPE",""+type);
switch(type){
case Config.START_NEW_MUSIC:
startNewMusic(intent);
break;
case Config.MUSIC_SEEK_TO:
if (player!=null){
int progress=intent.getIntExtra("progress",0);
player.pause();//暂停播放。
player.seekTo(progress);//寻找指定的时间位置。
Log.d("当前进度",""+progress);
player.start();//开始播放
}
break;
}

return super.onStartCommand(intent, flags, startId);
}

private void startNewMusic(Intent intent) {
String musicPath=intent.getStringExtra("musicName");
if (player==null){
player=new MediaPlayer();
}else{
player.seekTo(intent.getIntExtra("progess",0));
}
player.reset();//重置MediaPlayer的初始化状态。
try {
player.setDataSource(musicPath);
player.prepare();//准备播放，同步播放
//注册一个回调函数，当媒体源准备播放时调用。
player.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
mp.start();
int duration=player.getDuration();
Log.d("总时间",""+duration);
Intent intent=new Intent("com.play.music");
intent.putExtra("type",Config.START_NEW_MUSIC);
intent.putExtra("duration",duration);
sendBroadcast(intent);
MusicPlayThread t=new MusicPlayThread();
t.start();
}
});
} catch (IOException e) {
e.printStackTrace();
}
}

class MusicPlayThread extends Thread{
@Override
public void run() {
while(player.isPlaying()){
int time=player.getCurrentPosition();
Intent intent=new Intent("com.play.music");
intent.putExtra("type",1);
intent.putExtra("currtTime",time);
sendBroadcast(intent);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}

Config.java

public class Config {
public static final int START_NEW_MUSIC=0;
public static final int MUSIC_SEEK_TO=1;
}

MainActivity.java

public class MainActivity extends AppCompatActivity {
private ListView mlistMusic;
private Random mRandom;
private Button btn_play;
private File[] musics;
private SeekBar mSeekBar;
private int progress;
MyReceive myReceive;
private TextView mTime;
private TextView mNowTime;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mlistMusic= (ListView) findViewById(R.id.listview_music);
mSeekBar= (SeekBar) findViewById(R.id.seekbar_music);
mNowTime= (TextView) findViewById(R.id.text_timenow);
myReceive=new MyReceive();
IntentFilter filter=new IntentFilter();
filter.addAction("com.play.music");
registerReceiver(myReceive,filter);
mTime= (TextView) findViewById(R.id.text_time);
mRandom=new Random();
btn_play= (Button) findViewById(R.id.btn_play);
File sdcard= Environment.getExternalStorageDirectory();
File musicDir=new File(sdcard,"Music");
musics=musicDir.listFiles();
MyMusicAdapter mAdapter=new MyMusicAdapter(getLayoutInflater(),musics);
mlistMusic.setAdapter(mAdapter);
mlistMusic.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent intent=new Intent(MainActivity.this, MusicService.class);
intent.putExtra("musicName",musics[position].getAbsolutePath());
startService(intent);
}
});
btn_play.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {

}
});
mSeekBar.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) {
Intent intent=new Intent(getApplicationContext(),MusicService.class);
intent.putExtra("type",Config.MUSIC_SEEK_TO);
intent.putExtra("progress",seekBar.getProgress());
Log.d("progress",""+seekBar.getProgress());
startService(intent);
}
});
}

@Override
protected void onDestroy() {
super.onDestroy();
unregisterReceiver(myReceive);
}

class MyReceive extends BroadcastReceiver{

@Override
public void onReceive(Context context, Intent intent) {
int type=intent.getIntExtra("type",0);
SimpleDateFormat format=new SimpleDateFormat("mm:ss");

switch(type){
case Config.START_NEW_MUSIC:
int duration=intent.getIntExtra("duration",0);
mSeekBar.setMax(duration);
String timesum=format.format(duration);
mTime.setText(""+timesum);
break;
case Config.MUSIC_SEEK_TO:
int currentTime=intent.getIntExtra("currtTime",0);
mSeekBar.setProgress(currentTime);
String time=format.format(currentTime);
mNowTime.setText(""+time);
break;
}
}
}
}