【Android】系统按键音流程

按键音流程"/>

【Android】系统按键音流程

需求

系统按键音设置后不起作用，需要放开
系统：Android8.1

相关文件查找

布局文件

通过代码搜索“触摸提示音”，找到string对应的名称:“touch_sounds_title”，最后将文件定位到other_sound_settings.xml以及sound_settings.xml

<!-- Touch sounds --><SwitchPreferenceandroid:key="touch_sounds"android:title="@string/touch_sounds_title" />

java文件

通过touch_sounds定位到文件TouchSoundPreferenceController.java

流程

安卓设置中的声音设置页面

通过ARDC开启监测，定位到当前页面内的activity

找到Settings\AndroidManifest.xml

<activityandroid:name="Settings$SoundSettingsActivity"android:label="@string/sound_settings"android:icon="@drawable/ic_homepage_sound"android:exported="true"android:taskAffinity="com.android.settings"android:parentActivityName="Settings"><intent-filter android:priority="1"><action android:name="com.android.settings.SOUND_SETTINGS" /><action android:name="android.settings.SOUND_SETTINGS" /><action android:name="android.settings.ACTION_OTHER_SOUND_SETTINGS" /><category android:name="android.intent.category.DEFAULT" /></intent-filter><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.DEFAULT" /><category android:name="android.intent.category.VOICE_LAUNCH" /><category android:name="com.android.settings.SHORTCUT" /></intent-filter><intent-filter android:priority="6"><action android:name="com.android.settings.action.SETTINGS" /></intent-filter><meta-data android:name="com.android.settings.category"android:value="com.android.settings.category.ia.homepage" /><meta-data android:name="com.android.settings.FRAGMENT_CLASS"android:value="com.android.settings.notification.SoundSettings" /><meta-data android:name="com.android.settings.PRIMARY_PROFILE_CONTROLLED"android:value="true" /><meta-data android:name="com.android.settings.summary"android:resource="@string/sound_dashboard_summary"/></activity>

其中

<meta-data android:name="com.android.settings.FRAGMENT_CLASS"android:value="com.android.settings.notification.SoundSettings" />

表明点击会跳转至该页面(fragment)，也就是SoundSettings页面
里面有各种声音相关的设置，其中TouchSoundPreferenceController就是触摸提示音相关

TouchSoundPreferenceController

\packages\apps\Settings\src\com\android\settings\notification\TouchSoundPreferenceController.java

public TouchSoundPreferenceController(Context context, SettingsPreferenceFragment parent,Lifecycle lifecycle) {super(context, parent, lifecycle);mPreference = new SettingPref(TYPE_SYSTEM, KEY_TOUCH_SOUNDS, System.SOUND_EFFECTS_ENABLED, DEFAULT_ON) {@Overrideprotected boolean setSetting(final Context context, final int value) {AsyncTask.execute(new Runnable() {@Overridepublic void run() {final AudioManager am =(AudioManager) context.getSystemService(Context.AUDIO_SERVICE);if (value != 0) {am.loadSoundEffects();} else {am.unloadSoundEffects();}}});return super.setSetting(context, value);}};}

先对System属性值赋值

mPreference = new SettingPref(TYPE_SYSTEM, KEY_TOUCH_SOUNDS, System.SOUND_EFFECTS_ENABLED, DEFAULT_ON){};

PS:使用adb获取按键提示音的状态

adb shell settings get system sound_effects_enabled

监听按键的变化，来选择加载或关闭提示音

am.loadSoundEffects();
am.unloadSoundEffects();

进入framework层，调用系统服务等

framework

framework\base\media\java\android\media\AudioManager.java

public void loadSoundEffects() {final IAudioService service = getService();//获取AudioService对象try {service.loadSoundEffects();//调用AudioService中方法} catch (RemoteException e) {throw e.rethrowFromSystemServer();}}

private static IAudioService getService(){if (sService != null) {return sService;}IBinder b = ServiceManager.getService(Context.AUDIO_SERVICE);//通过binder调用AudioServicesService = IAudioService.Stub.asInterface(b);return sService;}

framework\base\services\core\java\com\android\server\audio\AudioService.java

public boolean loadSoundEffects() {int attempts = 3;LoadSoundEffectReply reply = new LoadSoundEffectReply();synchronized (reply) {sendMsg(mAudioHandler, MSG_LOAD_SOUND_EFFECTS, SENDMSG_QUEUE, 0, 0, reply, 0);while ((reply.mStatus == 1) && (attempts-- > 0)) {try {reply.wait(SOUND_EFFECTS_LOAD_TIMEOUT_MS);} catch (InterruptedException e) {Log.w(TAG, "loadSoundEffects Interrupted while waiting sound pool loaded.");Thread.currentThread().interrupt();}}}return (reply.mStatus == 0);}

其中，发送广播

sendMsg(mAudioHandler, MSG_LOAD_SOUND_EFFECTS, SENDMSG_QUEUE, 0, 0, reply, 0);

内部处理

private class AudioHandler extend Handler{...@Overridepublic void handleMessage(Message msg){switch(msg.what){case MSG_LOAD_SOUND_EFFECTS:boolean loaded = onLoadSoundEffects();//调用方法，加载音效if (msg.obj != null) {LoadSoundEffectReply reply = (LoadSoundEffectReply)msg.obj;synchronized (reply) {reply.mStatus = loaded ? 0 : -1;reply.notify();}}break;}}
}

同时也就是在这里，我找到了处理播放音效的方法，之前一直对System.SOUND_EFFECTS_ENABLED赋值不起作用，是该处将onPlaySoundEffect方法进行了屏蔽，放开，编译，刷机，成功，而且默认就是开启的

case MSG_PLAY_SOUND_EFFECT:onPlaySoundEffect(msg.arg1,msg.arg2);

至于为什么会关闭/隐藏该方法，之前合入三方应用的时候提过这个bug，开启之后会与其他应用冲突，所以选择了隐藏，触摸提示音时不走该方法

待定

• 点击后音效播放的加载、实现流程