How to detect Bluetooth state change using a broadcast receiver?

Question

I am trying to make an app that shows a toast when the device\'s Bluetooth turned on. I wanna do that even when my app is not running. So I should use a broadcast receiver,

Answer 1

AS far as permissions go, to detect the state change of bluetooth you need to add this to your AndroidManifest.xml.

An example receiver would look like this, you add this code to where you want to handle the broadcast, for example an activity:

    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
            public void onReceive (Context context, Intent intent) {
                String action = intent.getAction();

                if (BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)) {
                    if(intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, -1) 
    == BluetoothAdapter.STATE_OFF)
    // Bluetooth is disconnected, do handling here
}

}

        };

To use the receiver, you need to register it. Which you can do as follows. I register the receiver in my main activity.

registerReceiver(this, new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED));

You could also decide to add all of it to your AndroidManifest.xml. This way you can make a special class for the receiver and handle it there. No need to register the receiver, just make the class and add the below code to the AndroidManifest