mcdoomington mcdoomington - 1 month ago 8
Android Question

Android Marshmallow 6.0.1 Bluetooth Scan Returning No Results

Bluetooth in 6.01 seems to be not working as expected with the following code and permissions as per update + appCompat for Kitkat 4.4.4.

No results are being returned and I have several discoverable devices in the vicinity.

Anyone have any insight as per why? I am running on a Nexus 5.

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

package bluetoothscanneractivity;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;

public class BluetoothScannerActivity extends Activity {
//private final BroadcastReceiver FoundReceiver = null;
protected ArrayList<BluetoothDevice> foundDevices = new ArrayList<BluetoothDevice>();
private ListView foundDevicesListView;
private ArrayAdapter<BluetoothDevice> btArrayAdapter;

/**
* Called when the activity is first created.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bluetooth_scanner);
final BluetoothAdapter myBlueToothAdapter = BluetoothAdapter.getDefaultAdapter();
final Button scanb = (Button) findViewById(R.id.button);
final ListView foundDevicesListView = (ListView) findViewById(R.id.listView1);

btArrayAdapter = new ArrayAdapter<BluetoothDevice>(this,
android.R.layout.simple_list_item_1, foundDevices);
foundDevicesListView.setAdapter(btArrayAdapter);

//Turn on Bluetooth
if (myBlueToothAdapter == null)
Toast.makeText(BluetoothScannerActivity.this, "Your device doesnot support Bluetooth", Toast.LENGTH_LONG).show();
else if (!myBlueToothAdapter.isEnabled()) {
Intent BtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(BtIntent, 0);
Toast.makeText(BluetoothScannerActivity.this, "Turning on Bluetooth", Toast.LENGTH_LONG).show();
}
//scan
scanb.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
btArrayAdapter.clear();
myBlueToothAdapter.startDiscovery();
Toast.makeText(BluetoothScannerActivity.this, "Scanning Devices", Toast.LENGTH_LONG).show();

}
});

registerReceiver(FoundReceiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));
IntentFilter filter = new IntentFilter(
BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
this.registerReceiver(FoundReceiver, filter);

}

@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
unregisterReceiver(FoundReceiver);
}

private final BroadcastReceiver FoundReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {

String action = intent.getAction();

// When discovery finds a new device
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Get the BluetoothDevice object from the Intent
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
if (!foundDevices.contains(device)) {
foundDevices.add(device);
btArrayAdapter.notifyDataSetChanged();
}
}

// When discovery cycle finished
if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
if (foundDevices == null || foundDevices.isEmpty()) {
Toast.makeText(BluetoothScannerActivity.this, "No Devices", Toast.LENGTH_LONG).show();
}
}

}
};


}

Answer

With the added permissions, changing to min SDk version to 23 - it works with the following:

package bluetoothscanneractivity;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import android.Manifest;

import java.util.ArrayList;

public class BluetoothScannerActivity extends AppCompatActivity {
    //private final BroadcastReceiver FoundReceiver = null;
    protected ArrayList<BluetoothDevice> foundDevices = new ArrayList<BluetoothDevice>();
    private ListView foundDevicesListView;
    private ArrayAdapter<BluetoothDevice> btArrayAdapter;

    /**
     * Called when the activity is first created.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_bluetooth_scanner);
        final BluetoothAdapter myBlueToothAdapter = BluetoothAdapter.getDefaultAdapter();

        final Button scanb = (Button) findViewById(R.id.button);
        final ListView foundDevicesListView = (ListView) findViewById(R.id.listView1);

        btArrayAdapter = new ArrayAdapter<BluetoothDevice>(this,
                android.R.layout.simple_list_item_1, foundDevices);

        foundDevicesListView.setAdapter(btArrayAdapter);

        //Turn on Bluetooth
        if (myBlueToothAdapter == null)
            Toast.makeText(BluetoothScannerActivity.this, "Your device doesnt support Bluetooth", Toast.LENGTH_LONG).show();
        else if (!myBlueToothAdapter.isEnabled()) {
            Intent BtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(BtIntent, 0);
            Toast.makeText(BluetoothScannerActivity.this, "Turning on Bluetooth", Toast.LENGTH_LONG).show();
        }

        // Quick permission check
        int permissionCheck = this.checkSelfPermission("Manifest.permission.ACCESS_FINE_LOCATION");
        permissionCheck += this.checkSelfPermission("Manifest.permission.ACCESS_COARSE_LOCATION");
        if (permissionCheck != 0) {

            this.requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, 1001); //Any number
        }


        scanb.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                btArrayAdapter.clear();

                myBlueToothAdapter.startDiscovery();

                Toast.makeText(BluetoothScannerActivity.this, "Scanning Devices", Toast.LENGTH_LONG).show();

            }
        });

        registerReceiver(FoundReceiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));
        IntentFilter filter = new IntentFilter(
                BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        this.registerReceiver(FoundReceiver, filter);

    }

    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        unregisterReceiver(FoundReceiver);
    }


    private final BroadcastReceiver FoundReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {

            String action = intent.getAction();

            // When discovery finds a new device
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                // Get the BluetoothDevice object from the Intent
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                if (!foundDevices.contains(device)) {
                    foundDevices.add(device);
                    Toast.makeText(BluetoothScannerActivity.this, "name: " + device.getName() + " " + device.getAddress(), Toast.LENGTH_LONG).show();
                    btArrayAdapter.notifyDataSetChanged();
                }

            }

            // When discovery cycle finished
            if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                if (foundDevices == null || foundDevices.isEmpty()) {
                    Toast.makeText(BluetoothScannerActivity.this, "No Devices", Toast.LENGTH_LONG).show();
                }
            }

        }
    };


}
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