Android CALL关于电话音频和紧急电话设置和获取

获取音频服务，设置音源类型：电话类型和获取最大电话音量，响铃模式

private AudioManager mAudioManager;

mAudioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
mAudioManager.setStreamVolume(AudioManager.STREAM_VOICE_CALL,
mAudioManager.getStreamMaxVolume(AudioManager.STREAM_VOICE_CALL),
AudioManager.FLAG_ALLOW_RINGER_MODES);

发送广播：打开紧急电话，拨打112

startActivity(new Intent(Intent.ACTION_CALL_EMERGENCY)
.setData(Uri.fromParts(PhoneAccount.SCHEME_TEL, "112", null))
.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK));