Android: How to pass a Bluetooth connection to another Activity?

Question

I have my first Activity in which the BT connection is established. There is an option presented to the user and, based on their selection, a different Activity will load.

Answer 1

Have you tried using the Application object to store the Bluetooth connection in an object and using your Activities to get it?

Try something like this. (Note: I have never worked with Bluetooth on Android, so I don't know which relevant classes to use. In this case, I'll use BluetoothDevice, since it seems to be the right class based on the library documentation)

public class MyApplication extends Application {
    BluetoothDevice device;
    ...
    public synchronized BluetoothDevice getBtConnection() {
        if (device == null) {
            // construct a BluetoothDevice object and put it into variable device
        }
        return device;
    }
}

That way, your first activity just has to do this:

public class FirstActivity extends Activity {
    private BluetoothDevice device;
    ...
    @Override
    protected void onCreate(Bundle b) {
        super(b);
        ...
        device = ((MyApplication) getApplication()).getBtDevice();
        ...
    }
    ...
}

And then, any time your other Activities need to use that connection, they just need to call getBtDevice(), because FirstActivity already instantiated it.