问题描述
android otg连接外部音响调节音量后,重启后音量不是之前设置的音量
问题分析
通过分析AudioService.java之后我们发现在每次手机重启时,AudioService start 时都会去获取
mSafeUsbMediaVolumeIndex = getSafeUsbMediaVolumeIndex();
通过上面发现,当我们设置的音量大于保护音量时,重启手机,会自动将音量设置为保护音量之下。
修改:
// mSafeMediaVolumeDevices lists the devices for which safe media volume is enforced,
private final int mSafeMediaVolumeDevices = AudioSystem.DEVICE_OUT_WIRED_HEADSET |
AudioSystem.DEVICE_OUT_WIRED_HEADPHONE |
AudioSystem.DEVICE_OUT_USB_HEADSET;
to
// mSafeMediaVolumeDevices lists the devices for which safe media volume is enforced,
private final int mSafeMediaVolumeDevices = AudioSystem.DEVICE_OUT_WIRED_HEADSET |
AudioSystem.DEVICE_OUT_WIRED_HEADPHONE;