判断蓝牙是否打开

BluetoothAdapter blueadapter = BluetoothAdapter.getDefaultAdapter()；if (!blueadapter.enable()) {ToastUtils.showShort("请打开蓝牙");return;}

使用了FastBle库的情况下

BleManager.getInstance().init(getApplication());if (!BleManager.getInstance().isBlueEnable()) {ToastUtils.showShort("请打开蓝牙");return;}