how to wait till bluetooth turn on in android

Question

I need to turn on Bluetooth in an android device programmatically and wait till it on to proceed to next line of code.

My code is as below

if (!mBluetoothAdapter.isEnabled()) {
                Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                ctx.startActivity(enableBtIntent);
}

When doing like this, the code continue to execute from next line without waiting for bluetooth completely on. Is there any way to solve this? Can I add a look to check if bluetooth is on?

You could try to `startActivityForResult`, but I don't know what the result code would be if an error did occur for some strange reason — OneCricketeer, Apr 20 '16 at 06:06
Please write your full class so that we can answer it properly. — Lips_coder, Apr 20 '16 at 06:09
I would register a BroadcastReceiver to listen for state changes on the bluetooth adapter. This answer should solve your problem. http://stackoverflow.com/questions/9693755/detecting-state-changes-made-to-the-bluetoothadapter — the-ginger-geek, Apr 20 '16 at 06:12
use this link http://www.tutorialspoint.com/android/android_bluetooth.htm — Ramesh Bhati, Apr 20 '16 at 06:22
Thanks for your answers. Thanks @Neil I solved my problem using BroadcastReceiver — Vineesh, Apr 21 '16 at 04:46
@Neil You should probably add Your comment as an answer, or Vineesh You should post how You resolved Your problem. Just so it is easier to find solution and see that the question is answered. — morynicz, Apr 21 '16 at 07:36
@Vineesh please accept my answer as the solution to your question. — the-ginger-geek, Apr 21 '16 at 08:09

score 12 · Accepted Answer · answered Apr 21 '16 at 08:08

You can register a BroadcastReceiver to listen for state changes on the BluetoothAdapter.

First create a BroadcastReceiver that will listen for state changes

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

        if (action.equals(BluetoothAdapter.ACTION_STATE_CHANGED)) {
            final int bluetoothState = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE,
                                                BluetoothAdapter.ERROR);
            switch (bluetoothState) {
            case BluetoothAdapter.STATE_ON:
                //Bluethooth is on, now you can perform your tasks
                break;
            }
        }
    }
};

Then register the BroadcastReceiver with your Activity when it is created so that it can start receiving events.

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    //Set a filter to only receive bluetooth state changed events.
    IntentFilter filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
    registerReceiver(mReceiver, filter);
}

Remember to unregister the listener when the Activity is destroyed.

@Override
public void onDestroy() {
    super.onDestroy();
    unregisterReceiver(mReceiver);
}

Iamat8 · Answer 2 · 2016-04-20T09:04:50.297

5

You can use startActivityForResult() and check for whether resultCode is RESULT_OK in onActivityResult() with bluetooth permission in your Manifest file like..

mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (!mBluetoothAdapter.isEnabled()) {
    Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    startActivityForResult(enableIntent, 0);
}

onActivityResult

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if(resultCode == RESULT_OK){
        // bluetooth enabled                      
    }else{
        // show error
    }       
}

ACTION_REQUEST_ENABLE

edited Apr 20 '16 at 09:04

answered Apr 20 '16 at 06:32

Iamat8

3,888
9
25
35

@user3182143 what issue ? – Iamat8 May 06 '16 at 10:28
Please add the comments in above link.The Questioner tell you the problem. – user3182143 May 06 '16 at 12:42
@user3182143 still didnt get that – Iamat8 May 06 '16 at 13:08
This doesn't work for me, code still just executes, no waiting. – Essej Nov 29 '17 at 18:35

Ramesh Bhati · Answer 3 · 2016-04-20T06:35:43.483

3

Use this code Permissions on your menifest file

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

and code

if (!mBluetoothAdapter.isEnabled()) {
     Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
     startActivityForResult(enableBtIntent , 0);
  } else
  {
     Toast.makeText(getApplicationContext(),"Already on", Toast.LENGTH_LONG).show();
  }

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(resultCode == RESULT_OK){
    Toast.makeText(getApplicationContext(),"Turned on",Toast.LENGTH_LONG).show();
}
if(resultCode == RESULT_CANCELED){

}

edited Apr 20 '16 at 06:35

answered Apr 20 '16 at 06:31

Ramesh Bhati

1,239
16
25

Shouldn't you place the Toasting inside of an onActivityResult method? What you have is no different than simply using startActivity – OneCricketeer Apr 20 '16 at 06:32
see updaetd answer – Ramesh Bhati Apr 20 '16 at 09:12

score 0 · Answer 4 · answered Apr 20 '16 at 07:51

0

startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    //do your things
}

answered Apr 20 '16 at 07:51

Jovita

1
2

how to wait till bluetooth turn on in android

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