高通平台 android7.1 蓝牙的可见性设置

1、情景

        本机设备只打开蓝牙开关，但不停留在设置里面蓝牙页面时，其他设备扫描不到本机设备。

2、Android7.1中，默认的行为是，只有在设置里面的蓝牙页面，才会开启蓝牙的可见性；如果只是打开下拉栏的蓝牙快捷开关，是不会开启蓝牙可见性的。

3、需求：

        （1）打开蓝牙时，直接打开蓝牙可见性

        （2）不停留在设置里面蓝牙页面时，要扫描到本机设备

4、需求一的解决方案：

        打开蓝牙时，直接打开蓝牙可见性。如下：

路径：****/packages/apps/Bluetooth/src/com/android/bluetooth/btservice/AdapterProperties.java

void onBluetoothReady() {Log.d(TAG, "ScanMode =  " + mScanMode );Log.d(TAG, "State =  " + getState() );// When BT is being turned on, all adapter properties will be sent in 1// callback. At this stage, set the scan mode.synchronized (mObject) {if (getState() == BluetoothAdapter.STATE_TURNING_ON &&mScanMode == BluetoothAdapter.SCAN_MODE_NONE) {/* mDiscoverableTimeout is part of theadapterPropertyChangedCallback received beforeonBluetoothReady */if (mDiscoverableTimeout != 0)//setScanMode(AbstractionLayer.BT_SCAN_MODE_CONNECTABLE);setScanMode(AbstractionLayer.BT_SCAN_MODE_CONNECTABLE_DISCOVERABLE);else /* if timeout == never (0) at startup */setScanMode(AbstractionLayer.BT_SCAN_MODE_CONNECTABLE_DISCOVERABLE);/* though not always required, this keeps NV up-to date on first-boot after flash */setDiscoverableTimeout(mDiscoverableTimeout);}}}

    如上图：    将  setScanMode(AbstractionLayer.BT_SCAN_MODE_CONNECTABLE);  改为

        setScanMode(AbstractionLayer.BT_SCAN_MODE_CONNECTABLE_DISCOVERABLE);即可。

5、需求二的解决方案，如下：

路径：******/packages/apps/Settings/src/com/android/settings/bluetooth/BluetoothSettings.java

@Overridepublic void onPause() {super.onPause();if (mBluetoothEnabler != null) {mBluetoothEnabler.pause();}// Make the device only visible to connected devices.//mLocalAdapter.setScanMode(BluetoothAdapter.SCAN_MODE_CONNECTABLE);if (isUiRestricted()) {return;}getActivity().unregisterReceiver(mReceiver);}

如上图，在onPause()方法中将mLocalAdapter.setScanMode(BluetoothAdapter.SCAN_MODE_CONNECTABLE);注释掉即可。