How to save a list of discoverable bluetooth devices in android?

Question

I'm trying to get a list of disoverable bluetooth devices in android. I can get the devices and using an ArrayAdapter, populate a ListView of the devices. My question is, how do I save them to a list so I can use this information for another function? I've tried looking on the android developers site and all it has is the tutorial for the ListView. I've also looked for other tutorials or explanations and seem to be getting the wrong info.

My code is:

protected List<String> doInBackground(Void... arg0) {
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
mBluetoothAdapter.startDiscovery();

// Create a BroadcastReceiver for ACTION_FOUND
final List<String> discoverableDevicesList = new ArrayList<String>();

final BroadcastReceiver mReceiver = new BroadcastReceiver() {
    public void onReceive(Context context, Intent intent) {
        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);
            short rssi = intent.getShortExtra(BluetoothDevice.EXTRA_RSSI,Short.MIN_VALUE);
            // Add the name and address to an array adapter to show in a ListView
            System.out.println(device.getName());
            discoverableDevicesList.add(device.getName() + "\n" + device.getAddress() + "\n" + rssi);   
        }
    }
};
// Register the BroadcastReceiver
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
context.registerReceiver(mReceiver, filter); // Don't forget to unregister during onDestroy

return discoverableDevicesList;

}

It's probably something to do with the discover time associated with scanning for bluetooth devices, but I thought as each one was discovered I could just add it to the list? Has anyone come across something similar or have a possible solution? Much appreciated!

Have you tried saving in preferences? http://stackoverflow.com/questions/3876680/is-it-possible-to-add-an-array-or-object-to-sharedpreferences-on-android — Jack, Feb 27 '13 at 19:36

Keith Baton · Answer 1 · 2013-02-28T02:46:20.020

1

Looks like it could possibly have something to do with UI thread. Did you try firing off AsyncTask to populate the ListView on Bluetooth device discovery? I see you do:

           // Add the name and address to an array adapter to show in a ListView
        System.out.println(device.getName());
        discoverableDevicesList.add(device.getName() + "\n" + device.getAddress() + "\n" + rssi);

Inside of the Receiver but there is no guarantee that the UI thread is even ready for processing the response.

I'm getting this off of http://android-developers.blogspot.com/2009/05/painless-threading.html

edited Feb 28 '13 at 02:46

answered Feb 27 '13 at 19:41

Keith Baton

11
2

I did find one thing that helped, a bit off the subject but, I was implementing this as an Async Task and I ran into this post, http://stackoverflow.com/questions/11210420/bluetooth-discovery-inside-a-asynctask @Dewayne, does this affect what you're suggesting? – Aimee Jones Feb 28 '13 at 00:45
Yes, It would be hard to tell what exactly was going on with just the snippet you gave, the other poster answered it correctly regardless. – Keith Baton Feb 28 '13 at 02:46

How to save a list of discoverable bluetooth devices in android?

1 Answers1