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I cant connect to remote Bluetooth device. i can see paired and founded devices in ListView, but when i click on item(name of my PC or nexus 5) in the ListView nothing happens. Bluetoth pairing request window dont appears.

Manifest.xml

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

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">

    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>

</application>

activity_main.xml

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="10dp">

<LinearLayout
    android:layout_gravity="center_horizontal"
    android:orientation="horizontal"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <Button
        android:id="@+id/button_enable_BT"
        android:layout_marginRight="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/enableBT"/>

    <Button
        android:id="@+id/button_start_discovery"
        android:layout_marginRight="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/start_discovery_button"/>

    <Button
        android:id="@+id/button_stop_discovery"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/stop_discovery_button"/>

</LinearLayout>

<TextView
    android:id="@+id/status"
    android:hint="@string/status"
    android:layout_gravity="center_horizontal"
    android:layout_marginTop="10dp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:layout_marginTop="10dp"
    android:text="@string/paired_devices"/>

<ListView
    android:id="@+id/paired_list"
    android:layout_marginTop="10dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"/>
<LinearLayout

MainActivity.java

public class MainActivity extends Activity {
private final static int REQUEST_ENABLE_BT = 1;
private final static int REQUEST_COARSE_LOCATION_PERMISSIONS = 2;
UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
BluetoothAdapter mBluetoothAdapter;
ListView pairedList;
ListView newList;
Button mStart;
Button mStop;
Button mEnableBT;
TextView status;
ArrayAdapter<String> mArrayAdapter;
ArrayList<BluetoothDevice> devices;
IntentFilter filter;
String[] names;
ConnectThread mConnectThread;
ConnectedThread mConnectedThread;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    init();

    Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
    if (pairedDevices.size() > 0) {
        for (BluetoothDevice device : pairedDevices) {
            devices.add(device);
            mArrayAdapter.add(device.getName() + "\n" + device.getAddress());
        }
    }
    pairedList.setAdapter(mArrayAdapter);

    mStart.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            doDiscovery();
        }
    });
    mStop.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mBluetoothAdapter.cancelDiscovery();
        }
    });
    mEnableBT.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (!mBluetoothAdapter.isEnabled()) {
                Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
            }
        }
    });
    AdapterView.OnItemClickListener itemClickListener = new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            if(mBluetoothAdapter.isDiscovering()){
                mBluetoothAdapter.cancelDiscovery();
            }
            BluetoothDevice selectedDevice = devices.get(position);
            mConnectThread = new ConnectThread(selectedDevice);
            mConnectThread.start();

        }
    };
    pairedList.setOnItemClickListener(itemClickListener);

    filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
    registerReceiver(mReceiver, filter);
    filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
    registerReceiver(mReceiver, filter);
    filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
    registerReceiver(mReceiver, filter);
    filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
    registerReceiver(mReceiver, filter);
}

@Override
protected void onDestroy() {
    super.onDestroy();
    mBluetoothAdapter.cancelDiscovery();
    unregisterReceiver(mReceiver);
}

public void init(){
    names = new String[10];
    devices = new ArrayList<>();
    mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    status = (TextView)findViewById(R.id.status);
    mStart = (Button)findViewById(R.id.button_start_discovery);
    mStop = (Button)findViewById(R.id.button_stop_discovery);
    mEnableBT = (Button)findViewById(R.id.button_enable_BT);
    pairedList = (ListView)findViewById(R.id.paired_list);
    mArrayAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1);
}
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if(BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)) {
            int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, BluetoothAdapter.ERROR);
            if(BluetoothAdapter.STATE_ON == state){
                Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
                if (pairedDevices.size() > 0) {
                    for (BluetoothDevice device : pairedDevices) {
                        mArrayAdapter.add(device.getName() + "\n" + device.getAddress());
                        devices.add(device);
                    }
                }
            }
            if(BluetoothAdapter.STATE_OFF == state){
                mArrayAdapter.clear();
                devices.clear();
            }
        }
        if(BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)){
            status.setText("Discovery started");
        }
        if (BluetoothDevice.ACTION_FOUND.equals(action)) {
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            status.setText("Device found");
            if(device.getBondState() != BluetoothDevice.BOND_BONDED) {
                if(mArrayAdapter.getPosition(device.getName()+"\n"+device.getAddress()) < 0){
                    mArrayAdapter.add(device.getName()+"\n"+device.getAddress());
                    devices.add(device);
                    status.setText("!!!");
                }
            }
        }
        if(BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)){
            status.setText("Discovery stopped");
        }
    }
};
public void doDiscovery(){
    int hasPermission = checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION);
    if (hasPermission == PackageManager.PERMISSION_GRANTED) {
        if(mBluetoothAdapter.isDiscovering()){
            mBluetoothAdapter.cancelDiscovery();
        }
        mBluetoothAdapter.startDiscovery();
    }
    requestPermissions(new String[]{android.Manifest.permission.ACCESS_COARSE_LOCATION},
            REQUEST_COARSE_LOCATION_PERMISSIONS);
}
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    switch (requestCode) {
        case REQUEST_COARSE_LOCATION_PERMISSIONS: {
            if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                if(mBluetoothAdapter.isDiscovering()){
                    mBluetoothAdapter.cancelDiscovery();
                }
                mBluetoothAdapter.startDiscovery();
            } else {
                Toast.makeText(this,
                        getResources().getString(R.string.permission_failure),
                        Toast.LENGTH_LONG).show();
                mBluetoothAdapter.cancelDiscovery();
            }
            return;
        }
    }
}
public synchronized void connected(BluetoothSocket socket) {

    // Cancel the thread that completed the connection
    if (mConnectThread != null) {
        mConnectThread.cancel();
        mConnectThread = null;
    }

    // Cancel any thread currently running a connection
    if (mConnectedThread != null) {
        mConnectedThread.cancel();
        mConnectedThread = null;
    }

    // Start the thread to manage the connection and perform transmissions
    mConnectedThread = new ConnectedThread(socket);
    mConnectedThread.start();
}
private class ConnectThread extends Thread {
    private final BluetoothSocket mmSocket;
    private final BluetoothDevice mmDevice;

    public ConnectThread(BluetoothDevice device) {
        // Use a temporary object that is later assigned to mmSocket,
        // because mmSocket is final
        BluetoothSocket tmp = null;
        mmDevice = device;

        // Get a BluetoothSocket to connect with the given BluetoothDevice
        try {
            // MY_UUID is the app's UUID string, also used by the server code
            tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
        } catch (IOException e) { }
        mmSocket = tmp;
    }

    public void run() {
        // Cancel discovery because it will slow down the connection
        mBluetoothAdapter.cancelDiscovery();

        try {
            // Connect the device through the socket. This will block
            // until it succeeds or throws an exception
            mmSocket.connect();
        } catch (IOException connectException) {
            // Unable to connect; close the socket and get out
            try {
                mmSocket.close();
            } catch (IOException closeException) { }
            return;
        }

        // Do work to manage the connection (in a separate thread)
        connected(mmSocket);
    }
    /** Will cancel an in-progress connection, and close the socket */
    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) { }
    }
}
private class ConnectedThread extends Thread {
    private final BluetoothSocket mmSocket;
    private final InputStream mmInStream;
    private final OutputStream mmOutStream;

    public ConnectedThread(BluetoothSocket socket) {
        mmSocket = socket;
        InputStream tmpIn = null;
        OutputStream tmpOut = null;

        // Get the input and output streams, using temp objects because
        // member streams are final
        try {
            tmpIn = socket.getInputStream();
            tmpOut = socket.getOutputStream();
        } catch (IOException e) { }

        mmInStream = tmpIn;
        mmOutStream = tmpOut;
    }

    public void run() {
        byte[] buffer = new byte[1024];  // buffer store for the stream
        int bytes; // bytes returned from read()

        // Keep listening to the InputStream until an exception occurs
        while (true) {
            try {
                // Read from the InputStream
                bytes = mmInStream.read(buffer);
                // Send the obtained bytes to the UI activity

            } catch (IOException e) {
                break;
            }
        }
    }

    /* Call this from the main activity to send data to the remote device */
    public void write(byte[] bytes) {
        try {
            mmOutStream.write(bytes);
        } catch (IOException e) { }
    }

    /* Call this from the main activity to shutdown the connection */
    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) { }
    }
}

}

Alexander
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1 Answers1

0

For 6.0 (API 23) up, now you need to ask permissions on runtime, declaring them on the manifest is not enough. Because of that, you need to do something like this: https://stackoverflow.com/a/33052902/2328012

Hope it helps!

Community
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Diego Rivera
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