标签：surf 页面 媒体类型 dfa broadcast @param over ram save
Android多媒体框架支持各种常见的媒体类型，可以很容易地将音频、视频和图像集成到App中。通过MediaPlayer Api，可以从应用程序资源（RAW）、文件系统或网络上数据流资源来播放音频或视频。本文演示了如何通过Api播放音频和视频文件，来获得良好性能和愉快的用户体验，仅供学习分享使用，如有不足之处，还请指正。
页面上播放音频文件，步骤如下：
1. 准备资源文件，并播放
1 private MediaPlayer mMediaPlayer; 2 3 /** 4 * 开始 5 * @param v 6 */ 7 public void bn_start(View v){ 8 if(mMediaPlayer==null) { 9 ready(); 10 } 11 mMediaPlayer.start(); 12 } 13 14 /** 15 * 创建MediaPlayer并到prepare状态 16 */ 17 private void ready(){ 18 if(mMediaPlayer==null){ 19 mMediaPlayer=new MediaPlayer();//Idle 20 //Log.i("TAG", "ready: "+filePath); 21 File file=new File(Environment.getExternalStorageDirectory(),"goldfallen.mp3"); 22 Log.i("TAG", "ready: "+file.getPath()); 23 Log.i("TAG", "ready: "+file.exists()); 24 Uri uri= Uri.fromFile(file); 25 try { 26 mMediaPlayer.setDataSource(AudioActivity.this,uri); 27 mMediaPlayer.prepare();//Prepared 28 } catch (IOException e) { 29 Log.i("TAG", "ready: "+ e.getMessage()); 30 e.printStackTrace(); 31 } 32 } 33 }
2. 暂停播放
1 /** 2 * 暂停 3 * @param v 4 */ 5 public void bn_pause(View v){ 6 if(mMediaPlayer!=null && mMediaPlayer.isPlaying()){ 7 mMediaPlayer.pause(); 8 } 9 }
3. 停止
1 /** 2 * 停止 3 * @param v 4 */ 5 public void bn_stop(View v){ 6 if(mMediaPlayer!=null && mMediaPlayer.isPlaying()){ 7 mMediaPlayer.stop(); 8 mMediaPlayer.release(); 9 mMediaPlayer=null; 10 } 11 }
4. 释放资源（当页面销毁时，播放资源也要同时释放）
1 @Override 2 protected void onDestroy() { 3 if(mMediaPlayer!=null && mMediaPlayer.isPlaying()){ 4 mMediaPlayer.stop(); 5 mMediaPlayer.release(); 6 mMediaPlayer=null; 7 } 8 super.onDestroy(); 9 }
5. 通过静态函数创建对象
1 /** 2 * D:\Android\Project\DemoMedia\app\src\main\res\raw\A2012.mp3: 3 * Error: ‘A‘ is not a valid file-based resource name character: 4 * File-based resource names must contain only lowercase a-z, 0-9, or underscore 5 */ 6 private void ready2(){ 7 if(mMediaPlayer==null){ 8 mMediaPlayer= MediaPlayer.create(this,R.raw.ab2012); 9 } 10 }
当页面关闭时，音频文件还可以在后台播放。步骤如下：
1. 定义后台服务，当服务启动时，创建MediaPlayer对象，并注册服务接收对象。
1 public class AudioService extends Service { 2 3 private MediaPlayer mMediaPlayer; 4 5 private OperatorReceiver mReceiver; 6 7 public AudioService() { 8 } 9 10 @Override 11 public void onCreate() { 12 super.onCreate(); 13 mMediaPlayer=new MediaPlayer(); 14 mReceiver=new OperatorReceiver(); 15 IntentFilter filter=new IntentFilter("operator.receiver"); 16 registerReceiver(mReceiver,filter); 17 } 18 19 @Override 20 public IBinder onBind(Intent intent) { 21 return null; 22 } 23 24 @Override 25 public int onStartCommand(Intent intent, int flags, int startId) { 26 Log.i("TAG", "onStartCommand: ----ready "); 27 ready(); 28 return super.onStartCommand(intent, flags, startId); 29 } 30 31 @Override 32 public void onDestroy() { 33 if(mMediaPlayer!=null && mMediaPlayer.isPlaying()){ 34 mMediaPlayer.stop(); 35 } 36 if(mMediaPlayer!=null){ 37 mMediaPlayer.release(); 38 mMediaPlayer=null; 39 } 40 unregisterReceiver(mReceiver); 41 super.onDestroy(); 42 } 43 44 private void start(){ 45 mMediaPlayer.start(); 46 } 47 48 private void pause(){ 49 mMediaPlayer.pause(); 50 } 51 52 private void stop(){ 53 mMediaPlayer.stop(); 54 ready(); 55 } 56 57 private void ready(){ 58 mMediaPlayer.reset(); 59 try { 60 String filePath= Environment.getExternalStorageDirectory()+"/ab2012.mp3"; 61 Log.i("TAG", "ready: "+filePath); 62 File file=new File(filePath); 63 if(file.exists()) { 64 mMediaPlayer.setDataSource(filePath); 65 mMediaPlayer.prepare(); 66 }else{ 67 Log.i("TAG", "ready: 文件不存在 "); 68 } 69 } catch (IOException e) { 70 Log.i("TAG", "ready: "+e.getMessage()); 71 e.printStackTrace(); 72 } 73 } 74 }
2. 操作接收者定义如下：
1 /** 2 * 操作接收器 3 */ 4 class OperatorReceiver extends BroadcastReceiver 5 { 6 @Override 7 public void onReceive(Context context, Intent intent) { 8 int cmd=intent.getIntExtra("cmd",-1); 9 Log.i("TAG", "onReceive: "+cmd); 10 switch (cmd){ 11 case Tools.PLAY: 12 start(); 13 break; 14 case Tools.PAUSE: 15 pause(); 16 break; 17 case Tools.STOP: 18 stop(); 19 break; 20 default: 21 start(); 22 break; 23 24 } 25 } 26 }
3. 启动服务
1 Intent intent =new Intent(this,AudioService.class); 2 startService(intent);
4. 前台Activity通过发送广播命令进行控制音频的播放与暂停
1 /** 2 * 开始 3 * @param v 4 */ 5 public void bn_start(View v){ 6 Intent intent=new Intent("operator.receiver"); 7 intent.putExtra("cmd",Tools.PLAY); 8 sendBroadcast(intent); 9 Log.i("TAG", "bn_start: "+"service"); 10 } 11 12 /** 13 * 暂停 14 * @param v 15 */ 16 public void bn_pause(View v){ 17 Intent intent=new Intent("operator.receiver"); 18 intent.putExtra("cmd",Tools.PAUSE); 19 sendBroadcast(intent); 20 } 21 22 /** 23 * 停止 24 * @param v 25 */ 26 public void bn_stop(View v){ 27 Intent intent=new Intent("operator.receiver"); 28 intent.putExtra("cmd",Tools.STOP); 29 sendBroadcast(intent); 30 }
5.通过后台服务的方式，需要在AndroidManifest.xml文件中进行注册
1 <service 2 android:name=".AudioService" 3 android:enabled="true" 4 android:exported="true"> 5 </service>
通过VideoView进行播放视频文件，只需要设置资源URI即可，具体如下：
1 private VideoView mVideoView; 2 @Override 3 protected void onCreate(Bundle savedInstanceState) { 4 super.onCreate(savedInstanceState); 5 setContentView(R.layout.activity_video); 6 mVideoView= (VideoView) this.findViewById(R.id.vv_info); 7 //设置路径 8 File file=new File(Environment.getExternalStorageDirectory(),"DCIM/Camera/VID20190629142614.mp4"); 9 Log.i("TAG", "onCreate: "+file.getPath()); 10 if(!file.exists()){ 11 Log.i("TAG", "onCreate: 文件不存在"); 12 } 13 Uri uri=Uri.fromFile(file); 14 mVideoView.setVideoURI(uri); 15 //设置Media Controller 16 MediaController controller=new MediaController(this); 17 mVideoView.setMediaController(controller); 18 //获取焦点 19 mVideoView.requestFocus(); 20 mVideoView.start(); 21 //设置播放完成事件 22 mVideoView.setOnCompletionListener(new MediaPlayer.OnCompletionListener() { 23 @Override 24 public void onCompletion(MediaPlayer mp) { 25 Toast.makeText(VideoActivity.this, "播放完毕", Toast.LENGTH_SHORT).show(); 26 } 27 }); 28 }
通过MediaPlayer来播放视频文件，然后通过SurfaceView来显示视频内容，具体步骤如下：
1.启动，通过setDisplay来设置显示内容
1 public void bn_start(View view) { 2 mMediaPlayer.reset();//到Idle状态 3 //设置路径 4 File file=new File(Environment.getExternalStorageDirectory(),"DCIM/Camera/VID20190629142614.mp4"); 5 Log.i("TAG", "onCreate: "+file.getPath()); 6 if(!file.exists()){ 7 Log.i("TAG", "onCreate: 文件不存在"); 8 } else { 9 Log.i("TAG", "onCreate: 文件存在 "); 10 } 11 Uri uri=Uri.fromFile(file); 12 try { 13 mMediaPlayer.setDataSource(this,uri); 14 mMediaPlayer.setDisplay(mSurfaceView.getHolder()); 15 mMediaPlayer.prepare(); 16 mMediaPlayer.start(); 17 } catch (IOException e) { 18 e.printStackTrace(); 19 } 20 }
2. 暂停与停止
1 public void bn_pause(View view){ 2 if(mMediaPlayer.isPlaying()){ 3 mMediaPlayer.pause(); 4 } 5 } 6 7 public void bn_stop(View view){ 8 if(mMediaPlayer.isPlaying()){ 9 mMediaPlayer.stop(); 10 } 11 }
3. 资源释放
1 @Override 2 protected void onDestroy() { 3 if(mMediaPlayer!=null && mMediaPlayer.isPlaying()){ 4 mMediaPlayer.stop(); 5 } 6 if(mMediaPlayer!=null){ 7 mMediaPlayer.release(); 8 mMediaPlayer=null; 9 } 10 super.onDestroy(); 11 }
如果要播放视频，需要相应的权限设置，并在安装时获取请求权限
1 <uses-permission android:name="android.permission.INTERNET"/> 2 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> 3 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/> 4 <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
合抱之木，生于毫末；九层之台，起于垒土；千里之行，始于足下。
标签：surf 页面 媒体类型 dfa broadcast @param over ram save
原文地址：https://www.cnblogs.com/hsiang/p/11181673.html
