[移动开发]蓝牙通信之蓝牙扫描

1.声明蓝牙权限

<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

2.获取BluetoothAdapter

private lateinit var bluetoothAdapter: BluetoothAdapter

override fun onStart() {
    super.onStart()
    bluetoothAdapter = BluetoothAdapter.getDefaultAdapter()
}

?3.判断蓝牙是否开启，如果开启则开始扫描，如果未开启则通过动态请求打开蓝牙

if (!bluetoothAdapter.isEnabled) {
    val bIntent = Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE)
    startActivityForResult(bIntent, requestEnable)
} else {
    bluetoothAdapter.startDiscovery()
}

//获取权限后，开始扫描
override fun onRequestPermissionsResult(
    requestCode: Int,
    permissions: Array<out String>,
    grantResults: IntArray
) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults)
    Logger.e("ble--->$requestCode")
    if (requestCode == 1) {
        bluetoothAdapter.startDiscovery()
    }
}

?4.通过广播获取扫描的蓝牙信息

private val mBluetoothReceiver = object : BroadcastReceiver() {
    override fun onReceive(context: Context?, intent: Intent?) {
        val action = intent!!.action
        if (StringUtil.isSameStr(BluetoothDevice.ACTION_FOUND, action)) {
            val device: BluetoothDevice? =
                intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE)
            if (device != null) {
                scanDeviceList.add(device)
                scanDeviceAdapter.notifyDataSetChanged()
            }
        }
    }

}

5.注册广播，记得在onDestroy注销

val filter = IntentFilter()
//发现设备
filter.addAction(BluetoothDevice.ACTION_FOUND);
//设备连接状态改变
filter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
//蓝牙设备状态改变
filter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
registerReceiver(mBluetoothReceiver, filter)

//取消广播，关闭蓝牙扫描
override fun onDestroy() {
    super.onDestroy()
    bluetoothAdapter.cancelDiscovery()
    unregisterReceiver(mBluetoothReceiver)
    scope.cancel()
}