我已经挖掘了Android源代码,发现每次发生音频路由事件时,AudioRoutesInfo对象都基于MediaRouter中的内部updateAudioRoutes方法:
void updateAudioRoutes(AudioRoutesInfo newRoutes) {
if (newRoutes.mMainType != mCurAudioRoutesInfo.mMainType) {
mCurAudioRoutesInfo.mMainType = newRoutes.mMainType;
int name;
if ((newRoutes.mMainType&AudioRoutesInfo.MAIN_HEADPHONES) != 0
|| (newRoutes.mMainType&AudioRoutesInfo.MAIN_HEADSET) != 0) {
name = com.android.internal.R.string.default_audio_route_name_headphones;
} else if ((newRoutes.mMainType&AudioRoutesInfo.MAIN_DOCK_SPEAKERS) != 0) {
name = com.android.internal.R.string.default_audio_route_name_dock_speakers;
} else if ((newRoutes.mMainType&AudioRoutesInfo.MAIN_HDMI) != 0) {
name = com.android.internal.R.string.default_media_route_name_hdmi;
} else {
name = com.android.internal.R.string.default_audio_route_name;
}
sStatic.mDefaultAudioVideo.mNameResId = name;
dispatchRouteChanged(sStatic.mDefaultAudioVideo);
}
final int mainType = mCurAudioRoutesInfo.mMainType;
boolean a2dpEnabled;
try {
a2dpEnabled = mAudioService.isBluetoothA2dpOn();
} catch (RemoteException e) {
Log.e(TAG, "Error querying Bluetooth A2DP state", e);
a2dpEnabled = false;
}
if (!TextUtils.equals(newRoutes.mBluetoothName, mCurAudioRoutesInfo.mBluetoothName)) {
mCurAudioRoutesInfo.mBluetoothName = newRoutes.mBluetoothName;
if (mCurAudioRoutesInfo.mBluetoothName != null) {
if (sStatic.mBluetoothA2dpRoute == null) {
final RouteInfo info = new RouteInfo(sStatic.mSystemCategory);
info.mName = mCurAudioRoutesInfo.mBluetoothName;
info.mDescription = sStatic.mResources.getText(
com.android.internal.R.string.bluetooth_a2dp_audio_route_name);
info.mSupportedTypes = ROUTE_TYPE_LIVE_AUDIO;
sStatic.mBluetoothA2dpRoute = info;
addRouteStatic(sStatic.mBluetoothA2dpRoute);
} else {
sStatic.mBluetoothA2dpRoute.mName = mCurAudioRoutesInfo.mBluetoothName;
dispatchRouteChanged(sStatic.mBluetoothA2dpRoute);
}
} else if (sStatic.mBluetoothA2dpRoute != null) {
removeRouteStatic(sStatic.mBluetoothA2dpRoute);
sStatic.mBluetoothA2dpRoute = null;
}
}
if (mBluetoothA2dpRoute != null) {
if (mainType != AudioRoutesInfo.MAIN_SPEAKER &&
mSelectedRoute == mBluetoothA2dpRoute && !a2dpEnabled) {
selectRouteStatic(ROUTE_TYPE_LIVE_AUDIO, mDefaultAudioVideo, false);
} else if ((mSelectedRoute == mDefaultAudioVideo || mSelectedRoute == null) &&
a2dpEnabled) {
selectRouteStatic(ROUTE_TYPE_LIVE_AUDIO, mBluetoothA2dpRoute, false);
}
}
}
不幸的是,我发现的唯一暴露于MediaRouter回调中的设备类型的是设备的内部字符串资源名称(例如电话或耳机)。但是,你可以看到,这个AudioRoutesInfo对象引用了该设备是否是耳机,HDMI等。
有没有人找到解决方案来获取这些信息?我找到的最好方法是使用内部资源名称,这非常难看。上帝,如果他们只提供AudioRoutesInfo对象,就可以访问所有这些信息,而不必依赖资源黑客。