Register broadcast receiver dynamically does not work - BluetoothDevice.ACTION_FOUND

Question

Using Log class to track Runtime show that onReceive() methode does not called,why ?

Register broadcast receiver dynamically

 private void discoverDevices () {
    Log.e("MOHAB","BEFORE ON RECEIVE");

     mReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            Log.e("MOHAB","ON RECEIVE");
            String action = intent.getAction();
            // When discovery finds a device
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                // Get the BluetoothDevice object from the Intent
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                // Add the name and address to an array adapter to show in a ListView
                Bluetooth b = new Bluetooth(device.getName(),device.getAddress());
                list.add(b);
            }
        }
    };
    Log.e("MOHAB","create intentFilter");
    // Register the BroadcastReceiver
    IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
    registerReceiver(mReceiver, filter); // Don't forget to unregister during onDestroy

}

Answer 1

What you missed is that you need to start a device discovery

First, get the bluetooth adapter

BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();

After that, you start the discovery by calling

mBtAdapter.startDiscovery();

You should read the details here as well, e.g. about cancelDiscovery() http://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html#startDiscovery%28%29

P.S. Also, it is suggested to use context.getSystemService(Context.BLUETOOTH_SERVICE) to get the BluetoothAdapter on API 18+, according to official doc.

To get a BluetoothAdapter representing the local Bluetooth adapter, when running on JELLY_BEAN_MR1 and below, call the static getDefaultAdapter() method; when running on JELLY_BEAN_MR2 and higher, retrieve it through getSystemService(Class) with BLUETOOTH_SERVICE.

Edit: Be reminded that you need BLUETOOTH_ADMIN permission to startDiscovery()