A. setVolumeControlStream(AudioManager.STREAM_MUSIC);
http://developer.android.com/training/managing-audio/volume-playback.html
http://developer.android.com/reference/android/app/Activity.html#setVolumeControlStream(int)
public final void setVolumeControlStream (int streamType)
Added in API level 1
Suggests an audio stream whose volume should be changed by the hardware volume controls.
The suggested audio stream will be tied to the window of this Activity. Volume requests which are received while the Activity is in the
foreground will affect this stream.
It is not guaranteed that the hardware volume controls will always change this stream's volume (for example, if a call is in progress, its
stream's volume may be changed instead). To reset back to the default, use USE_DEFAULT_STREAM_TYPE.
Parameters
streamType
The type of the audio stream whose volume should be changed by the hardware volume controls.
AudioManager的值:http://developer.android.com/reference/android/media/AudioManager.html
int STREAM_MUSIC The audio stream for music playback
B.getAssets ()
http://developer.android.com/reference/android/content/res/Resources.html#getAssets()
public final AssetManager getAssets ()
Added in API level 1
Retrieve underlying AssetManager storage for these resources.
C.AssetManager
http://developer.android.com/reference/android/content/res/AssetManager.html
D.AssetFileDescriptor
http://developer.android.com/reference/android/content/res/AssetFileDescriptor.html
E.SoundPool
http://developer.android.com/reference/android/media/SoundPool.html
The SoundPool class manages and plays audio resources for applications.
A SoundPool is a collection of samples that can be loaded into memory from a resource inside the APK or from a file in the file system. The
SoundPool library uses the MediaPlayer service to decode the audio into a raw 16-bit PCM mono or stereo stream. This allows applications to
ship with compressed streams without having to suffer the CPU load and latency of decompressing during playback.
http://developer.android.com/reference/android/media/SoundPool.html#SoundPool(int, int, int)
Parameters
maxStreams
the maximum number of simultaneous streams for this SoundPool object
streamType
the audio stream type as described in AudioManager For example, game applications will normally use STREAM_MUSIC.
srcQuality
the sample-rate converter quality. Currently has no effect. Use 0 for the default.
Returns
a SoundPool object, or null if creation failed
F.MediaPlayer
http://developer.android.com/reference/android/media/MediaPlayer.html
G.MediaPlayer.OnCompletionListener
http://developer.android.com/reference/android/media/MediaPlayer.OnCompletionListener.html
package com.badlogic.androidgames.framework; public interface Sound { public void play(float volume); public void dispose(); }
package com.badlogic.androidgames.framework; public interface Music { public void play(); public void stop(); public void pause(); public void setLooping(boolean looping); public void setVolume(float volume); public boolean isPlaying(); public boolean isStopped(); public boolean isLooping(); public void dispose(); }
package com.badlogic.androidgames.framework; public interface Audio { public Music newMusic(String filename); public Sound newSound(String filename); }
package com.badlogic.androidgames.framework.impl; import java.io.IOException; import android.content.res.AssetFileDescriptor; import android.media.MediaPlayer; import android.media.MediaPlayer.OnCompletionListener; import com.badlogic.androidgames.framework.Music; public class AndroidMusic implements Music, OnCompletionListener { MediaPlayer mediaPlayer; boolean isPrepared = false; public AndroidMusic(AssetFileDescriptor assetDescriptor) { mediaPlayer = new MediaPlayer(); try { mediaPlayer.setDataSource(assetDescriptor.getFileDescriptor(), assetDescriptor.getStartOffset(), assetDescriptor.getLength()); mediaPlayer.prepare(); isPrepared = true; mediaPlayer.setOnCompletionListener(this); } catch (Exception e) { throw new RuntimeException("Couldn't load music"); } } @Override public void dispose() { if (mediaPlayer.isPlaying()) mediaPlayer.stop(); mediaPlayer.release(); } @Override public boolean isLooping() { return mediaPlayer.isLooping(); } @Override public boolean isPlaying() { return mediaPlayer.isPlaying(); } @Override public boolean isStopped() { return !isPrepared; } @Override public void pause() { if (mediaPlayer.isPlaying()) mediaPlayer.pause(); } @Override public void play() { if (mediaPlayer.isPlaying()) return; try { synchronized (this) { if (!isPrepared) mediaPlayer.prepare(); mediaPlayer.start(); } } catch (IllegalStateException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } @Override public void setLooping(boolean isLooping) { mediaPlayer.setLooping(isLooping); } @Override public void setVolume(float volume) { mediaPlayer.setVolume(volume, volume); } @Override public void stop() { mediaPlayer.stop(); synchronized (this) { isPrepared = false; } } @Override public void onCompletion(MediaPlayer arg0) { synchronized (this) { isPrepared = false; } } }
package com.badlogic.androidgames.framework.impl; import android.media.SoundPool; import com.badlogic.androidgames.framework.Sound; public class AndroidSound implements Sound { int soundId; SoundPool soundPool; public AndroidSound(SoundPool soundPool,int soundId) { this.soundId = soundId; this.soundPool = soundPool; } @Override public void play(float volume) { soundPool.play(soundId, volume, volume, 0, 0, 1); } @Override public void dispose() { soundPool.unload(soundId); } }
package com.badlogic.androidgames.framework.impl; import java.io.IOException; import android.app.Activity; import android.content.res.AssetFileDescriptor; import android.content.res.AssetManager; import android.media.AudioManager; import android.media.SoundPool; import com.badlogic.androidgames.framework.Audio; import com.badlogic.androidgames.framework.Music; import com.badlogic.androidgames.framework.Sound; public class AndroidAudio implements Audio { AssetManager assets; SoundPool soundPool; public AndroidAudio(Activity activity) { activity.setVolumeControlStream(AudioManager.STREAM_MUSIC); this.assets = activity.getAssets(); this.soundPool = new SoundPool(20, AudioManager.STREAM_MUSIC, 0); } @Override public Music newMusic(String filename) { try { AssetFileDescriptor assetDescriptor = assets.openFd(filename); return new AndroidMusic(assetDescriptor); } catch (IOException e) { throw new RuntimeException("Couldn't load music '" + filename + "'"); } } @Override public Sound newSound(String filename) { try { AssetFileDescriptor assetDescriptor = assets.openFd(filename); int soundId = soundPool.load(assetDescriptor, 0); return new AndroidSound(soundPool, soundId); } catch (IOException e) { throw new RuntimeException("Couldn't load sound '" + filename + "'"); } } }
本文浅述了“beginning-android-games”书本的相关基础知识和相关类的设计分析,
书本和源码:http://download.csdn.net/detail/yangzhenping/8420261
本篇中的类实现来自“beginning-android-games\ch07-gl-basics”