I'm currently working on an android app to control Bluetooth devices but no available devices show up even though I can find them from the built-in settings>bluetooth menu.
I initially followed the android starter sample out of the box, but couldn't make it work. I then came across several similar posts and tried those as well, but still couldn't make it work. This is my code so far: ```
public class MainActivity extends AppCompatActivity {
private static final int REQUEST_LOCATION_BT = 3;
private static final int REQUEST_ENABLE_BT = 2;
private BluetoothAdapter bluetoothAdapter;
private ArrayList<String> deviceList;
private ActivityMainBinding binding;
private ArrayAdapter<String> listAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
binding = ActivityMainBinding.inflate(getLayoutInflater());
setContentView(binding.getRoot());
requiredSetup();
setupListView();
}
private void setupListView() {
Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();
deviceList = new ArrayList<>();
if (pairedDevices.size() > 0) {
// There are paired devices. Get the name and address of each paired device.
for (BluetoothDevice device : pairedDevices) {
deviceList.add(device.getName());
//String deviceHardwareAddress = device.getAddress(); // MAC address
}
}
listAdapter = new ArrayAdapter<>(this,
android.R.layout.simple_list_item_1, deviceList);
binding.listView.setAdapter(listAdapter);
}
private void requiredSetup() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
if (ContextCompat.checkSelfPermission(getApplicationContext(),
Manifest.permission.ACCESS_BACKGROUND_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(
MainActivity.this,
new String[]{Manifest.permission.ACCESS_BACKGROUND_LOCATION},
REQUEST_LOCATION_BT);
}
}
// checking if device supports bluetooth
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (bluetoothAdapter == null) {
// Device doesn't support Bluetooth
Toast.makeText(this, "Device doesnt support bluetooth", Toast.LENGTH_SHORT).show();
return;
}
// enabling bluetooth if disabled
if (!bluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, #Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REQUEST_ENABLE_BT && resultCode == RESULT_OK) {
Toast.makeText(this, "Bluetooth enabled", Toast.LENGTH_SHORT).show();
} else if (requestCode == REQUEST_ENABLE_BT && resultCode == RESULT_CANCELED) {
Toast.makeText(this, "App requires bluetooth to function", Toast.LENGTH_SHORT).show();
}
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String permissions[], #NonNull int[] grantResults) {
if (requestCode == REQUEST_LOCATION_BT) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Permission granted, yay! Start the Bluetooth device scan.
startScan();
} else {
// Alert the user that this application requires the location permission to perform the scan.
Toast.makeText(this, "Requires location permission to work", Toast.LENGTH_SHORT).show();
}
}
}
/**
* initializes device discovery. The list of devices are sent to the broadcast receiver
* The discovery process usually involves an inquiry scan of about 12 seconds,
* followed by a page scan of each device found to retrieve its Bluetooth name.
*/
private void startScan() {
// If we're already discovering, stop it
if (bluetoothAdapter.isDiscovering()) {
Toast.makeText(this, "stopping discovery", Toast.LENGTH_SHORT).show();
bluetoothAdapter.cancelDiscovery();
} else {
try {
// Register for broadcasts when a device is discovered
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(mReceiver, filter);
// Request discover from BluetoothAdapter
bluetoothAdapter.startDiscovery();
binding.progressBar.setVisibility(View.VISIBLE);
} catch (IllegalArgumentException e) {
e.printStackTrace();
Toast.makeText(this, "receivers not registered", Toast.LENGTH_SHORT).show();
}
}
}
/**
* #param view the button view that is pressed and the scanning begins
*/
public void searchDevices(View view) {
// checking if location permissions enabled
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, REQUEST_LOCATION_BT);
} else {
startScan();
}
}
/**
* The BroadcastReceiver that listens for discovered devices and changes the title when
* discovery is finished
*/
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
Toast.makeText(getApplicationContext(), "reeiver working", Toast.LENGTH_SHORT).show();
// When discovery finds a device
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Get the BluetoothDevice object from the Intent
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// If it's already paired, skip it, because it's been listed already
if (device != null && device.getBondState() != BluetoothDevice.BOND_BONDED) {
listAdapter.add(device.getName() + "\n" + device.getAddress());
Log.i("NEW DEVICE", device.getName());
listAdapter.notifyDataSetChanged();
}
// When discovery is finished, change the Activity title
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
//setProgressBarIndeterminateVisibility(false);
//setTitle(R.string.select_device);
binding.progressBar.setVisibility(View.INVISIBLE);
if (listAdapter.getCount() == 0) {
Toast.makeText(context, "no devices found", Toast.LENGTH_SHORT).show();
}
} else if (BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)) {
Toast.makeText(context, "Bluetooth state changed", Toast.LENGTH_SHORT).show();
} else if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
Toast.makeText(context, "Discovery started", Toast.LENGTH_SHORT).show();
}
}
};
#Override
protected void onDestroy() {
super.onDestroy();
// Make sure we're not doing discovery anymore
if (bluetoothAdapter != null) {
bluetoothAdapter.cancelDiscovery();
}
// Unregister broadcast listeners
this.unregisterReceiver(mReceiver);
}}
This is my manifest permissions:
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
This is my repository. It would be very helpful if anyone could shed some light here.
It seems like the code was just fine. The problem was with the target SDK version. Upon changing the version from 30 to 28, it worked. Thanks to MatejC's answer.
Related
I am coding an app to discover nearby Bluetooth devices. However, I am unable to pick up any devices near me. I have scoured the internet and debugged and found out that after calling the registerReceiver(mBroadcastReceiver3, discoverDevicesIntent) method, nothing happened. My BroadcastReceiver's onReceive is not being passed. I have already requested the required permissions in the manifest and on runtime aswell and even checked if the required permissions are granted (which they are) but to no avail. I am unsure why my BroadcastReceiver is not receiving. Below is my code.
Broadcast Receiver:
private BroadcastReceiver mBroadcastReceiver3 = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
Log.d(TAG, "mBroadCastReceiver3 Received.");
if (action.equals(BluetoothDevice.ACTION_FOUND)){
BluetoothDevice device = intent.getParcelableExtra (BluetoothDevice.EXTRA_DEVICE);
mBTDevices.add(device);
Log.d(TAG, "onReceive: " + device.getName() + ": " + device.getAddress());
mDeviceListAdapter = new DeviceListAdapter(context, R.layout.device_adapter_view, mBTDevices);
lvNewDevices.setAdapter(mDeviceListAdapter);
}
}
OnClick Function:
public void btnDiscover(View view) {
Log.d(TAG, "btnDiscover: Looking for unpaired devices.");
if(mBluetoothAdapter.isDiscovering()){
mBluetoothAdapter.cancelDiscovery();
Log.d(TAG, "btnDiscover: Canceling discovery.");
}
checkBTPermissions();
mBluetoothAdapter.startDiscovery();
Log.d(TAG, "mBluetoothAdapter: started discovery.");
IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
Log.d(TAG, "discoverDevicesIntent: IntentFilter established with value of: " + discoverDevicesIntent);
registerReceiver(mBroadcastReceiver3, discoverDevicesIntent);
Log.d(TAG, "mBroadcastReceiver3: receiver registered with discoverDevicesIntent.");
}
Checking of Permissions:
private void checkBTPermissions() {
Log.d(TAG, "checkBTPermissions: checking BT Permissions.");
if(Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP){
int permissionCheck = 0;
permissionCheck += this.checkSelfPermission("Manifest.permission.BLUETOOTH");
permissionCheck += this.checkSelfPermission("Manifest.permission.BLUETOOTH_ADMIN");
permissionCheck += this.checkSelfPermission("Manifest.permission.ACCESS_FINE_LOCATION");
permissionCheck += this.checkSelfPermission("Manifest.permission.ACCESS_COARSE_LOCATION");
if (permissionCheck != 0) {
Log.d(TAG, "permissionCheck: !=0 .");
this.requestPermissions(new String[]{Manifest.permission.BLUETOOTH, Manifest.permission.BLUETOOTH_ADMIN, Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION}, 1000);
}
}else{
Log.d(TAG, "checkBTPermissions: No need to check permissions. SDK version < LOLLIPOP.");
}
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == PERMISSION_CODE) {
if (grantResults.length > 0) {
int grantresultslength = grantResults.length;
Log.v(TAG, "" + grantresultslength);
for(int i=0; i<grantresultslength; i++){
if (grantResults[i] == PackageManager.PERMISSION_GRANTED){
Log.v(TAG,"PERMISSION" + i + " GRANTED");
}else{
Log.v(TAG,"PERMISSION" + i + " DENIED");
}
}
} else {
Toast.makeText(this, "PERMISSION DENIED", Toast.LENGTH_SHORT).show();
}
}
}
I´ve got stuck on a problem. I´ve tried some hints from Stack Overflow and other websites.
I would like to program an app, which searches for all Bluetooth devices around and if the matching device has been found (MAC-Address as reference), the app will start a connection.
Therefore I have programmed a test application to test the discovery-function. BUT there is unfortunately a big problem with starting the discovering process on my Android 10 device. I´ve got an older Samsung S3 Mini with Android 4.1.2 (SDK 16) on it, where my code is working fine.
On the Android 10 device startDiscovery() returns false, different to the Android 4 device, which returns true. On the android developer page they say, that false is the returning value, if an error has occurred. The BroadcastReceiver should work fine, because the app on the Android 9 mobile phone detects that a Bluetooth search has been started in the settings. It is only the startDiscovery() function, which the problem is all about (in my opinion).
I am checking all permissions and the Bluetooth state before starting the discovering-process. But i think, it can´t be the written code, because it works perfectly on the older device. Maybe I have something missing for newer devices.
Edit
As Thomas Morris explains below, in Android 10 you need the location turned on by the user. In Android 9 or lower, Thomas Morris answer is correct, because in all SDKs below 29, only the permission is needed and not the enabled location service.
Is there a solution to avoid asking the user to turn on the location themselves?
This is my MainActivity:
public class MainActivity extends AppCompatActivity {
final String TAG = "MainActivity";
BluetoothAdapter bluetoothAdapter;
int status = 0; //0 = start discovering, 1 = cancel discovering
public static final int REQUEST_ACCESS_COARSE_LOCATION = 1;
public static final int REQUEST_ENABLE_BLUETOOTH = 11;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
registerReceiver(receiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));
registerReceiver(receiver, new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_STARTED));
registerReceiver(receiver, new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED));
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
checkBluetoothState();
final Button test = findViewById(R.id.testbutton);
test.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(status == 0) {
if(bluetoothAdapter != null && bluetoothAdapter.isEnabled()) {
if (checkCoarseLocationPermission()) {
Boolean result = bluetoothAdapter.startDiscovery(); //start discovering and show result of function
Toast.makeText(getApplicationContext(), "Start discovery result: " + result, Toast.LENGTH_SHORT).show();
Log.d(TAG, "Start discovery: " + result);
test.setText("Stop");
status = 1;
}
}else{
checkBluetoothState();
}
}else{
Log.d(TAG,"Stop");
status = 0;
bluetoothAdapter.cancelDiscovery();
test.setText("Start");
}
}
});
checkCoarseLocationPermission();
}
private boolean checkCoarseLocationPermission() {
//checks all needed permissions
if(ContextCompat.checkSelfPermission(this,Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED){
ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.ACCESS_COARSE_LOCATION}, REQUEST_ACCESS_COARSE_LOCATION);
return false;
}else{
return true;
}
}
private void checkBluetoothState() {
//checks if bluetooth is available and if it´s enabled or not
if(bluetoothAdapter == null){
Toast.makeText(getApplicationContext(), "Bluetooth not available", Toast.LENGTH_SHORT).show();
}else{
if(bluetoothAdapter.isEnabled()){
if(bluetoothAdapter.isDiscovering()){
Toast.makeText(getApplicationContext(), "Device is discovering...", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(getApplicationContext(), "Bluetooth is enabled", Toast.LENGTH_SHORT).show();
}
}else{
Toast.makeText(getApplicationContext(), "You need to enabled bluetooth", Toast.LENGTH_SHORT).show();
Intent enabledIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enabledIntent, REQUEST_ENABLE_BLUETOOTH);
}
}
}
// Create a BroadcastReceiver for ACTION_FOUND.
private final BroadcastReceiver receiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Discovery has found a device. Get the BluetoothDevice
// object and its info from the Intent.
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
String deviceName = device.getName();
String deviceHardwareAddress = device.getAddress(); // MAC address
Log.d(TAG,"Device found: " + deviceName + "|" + deviceHardwareAddress);
Toast.makeText(getApplicationContext(), "FOUND: " + deviceName + "|" + deviceHardwareAddress, Toast.LENGTH_SHORT).show();
}
if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
//report user
Log.d(TAG,"Started");
Toast.makeText(getApplicationContext(), "STARTED", Toast.LENGTH_SHORT).show();
}
if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
//change button back to "Start"
status = 0;
final Button test = findViewById(R.id.testbutton);
test.setText("Start");
//report user
Log.d(TAG,"Finished");
Toast.makeText(getApplicationContext(), "FINISHED", Toast.LENGTH_SHORT).show();
}
if(BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)){
final int extra = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE,-1);
if(extra == (BluetoothAdapter.STATE_ON)) {
if (bluetoothAdapter.isDiscovering()) {
bluetoothAdapter.cancelDiscovery();
}
Boolean b = bluetoothAdapter.startDiscovery();
Toast.makeText(getApplicationContext(), "Start discovery" + b, Toast.LENGTH_SHORT).show();
}
}
}
};
#Override
protected void onDestroy() {
super.onDestroy();
if (bluetoothAdapter.isDiscovering()){
bluetoothAdapter.cancelDiscovery();
}
unregisterReceiver(receiver);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data){
super.onActivityResult(requestCode,resultCode,data);
if(requestCode == REQUEST_ENABLE_BLUETOOTH){
checkBluetoothState();
}
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults){
super.onRequestPermissionsResult(requestCode,permissions,grantResults);
switch (requestCode){
case REQUEST_ACCESS_COARSE_LOCATION:
if(grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
Toast.makeText(getApplicationContext(),"Permission granted",Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(getApplicationContext(),"Permission denied",Toast.LENGTH_SHORT).show();
}
}
}
}
This is my Manifest:
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
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>
<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
Enable location permission on the application. To do this go to:
Android phone settings
App & notifications
See all app
Locate your application and select it
Permissions
Allow location slide it on
Then
Turn bluetooth on the device on
Turn location on the device on
Or some code to do it automatically via a popup (call in oncreate method)
public void checkPermission() {
if (Build.VERSION.SDK_INT >= 23) {
if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED && checkSelfPermission(android.Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
} else {
ActivityCompat.requestPermissions(this, new String[]{
Manifest.permission.ACCESS_FINE_LOCATION,
Manifest.permission.ACCESS_COARSE_LOCATION,}, 1);
}
}
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
if (requestCode == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
} else {
checkPermission();
}
}
Starting Android 10 the Location service must be enabled otherwise no devices will be found.
I tested BluetoothAdapter.startDiscovery() on Huawei P30 with Android 10 and this method alway return false but really the discovery is started (with Location permission granted and location service enabled). So i don't check the result of startDiscovery() method.
According to the official Android Documentation you need to have both ACCESS_FINE_LOCATION and ACCESS_BACKGROUND_LOCATION permissions to start discovering Bluetooth devices.
/**
* From Android 10 onwards it needs Access Location to search Bluetooth Devices
*/
private void checkForLocationPermission(){
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED && checkSelfPermission(android.Manifest.permission.ACCESS_BACKGROUND_LOCATION) == PackageManager.PERMISSION_GRANTED) {
discoverDevices();
} else {
ActivityCompat.requestPermissions(this, new String[]{
Manifest.permission.ACCESS_FINE_LOCATION,
Manifest.permission.ACCESS_BACKGROUND_LOCATION,}, 1);
}
}
}
/**
* Request Access Location while using the App, because bluetooth need location to start discovering devices
* #param requestCode
* #param permissions
* #param grantResults
*/
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
discoverDevices();
} else {
checkForLocationPermission();
}
}
The above code snippet will help you to request the above permissions from the user.
P.S: Also, these need to specified on the Android Manifest as well.
I have an app used for Bluetooth control of an embedded system using the SPP protocol that has worked fine until Marshmallow. If Bluetooth is enabled when I start the app everything is good. I use startActivityForResult() to prompt the user to allow Bluetooth to be enabled if it's not already. It used to block until a result was given but under Marshmallow it blows through it and crashes immediately with a null pointer exception. I added a "hack" in onResume() to keep it from doing this by returning if not enabled, but am wondering if this is poor practice?
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btAdapter = BluetoothAdapter.getDefaultAdapter();
if (btAdapter == null) {
Toast.makeText(getApplicationContext(), "No bluetooth detected", Toast.LENGTH_SHORT).show();
finish();
} else {
if (!btAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, ENABLE_BT_REQUEST_CODE);
}
}
}
#Override
public void onResume() {
super.onResume();
/* This keeps from crashing immediately if BT not enabled */
if (!btAdapter.isEnabled()) {
return;
};
if (btAdapter.isDiscovering()) {
btAdapter.cancelDiscovery();
}
// Rest of code .......
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// Check Result from turnOnBT()
if (requestCode == ENABLE_BT_REQUEST_CODE) {
if (resultCode == RESULT_CANCELED) {
Toast.makeText(getApplicationContext(), "Bluetooth must be enabled to continue", Toast.LENGTH_SHORT).show();
finish();
}
}
}
Whenever I start/resume my android phone app, it will prompt me to enable my bluetooth twice, regardless what I choose on the first prompt message. What is wrong with my code?
public class MainActivity extends AppCompatActivity {
// BLE management
private static BluetoothManager btManager;
private static BluetoothAdapter btAdapter;
// Set the enable bluetooth code
private final static int REQUEST_ENABLE_BT = 0;
// String for LogCat documentation
private final static String DEBUG_TAG= "";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
btAdapter = btManager.getAdapter();
if (btAdapter != null) {
if (!btAdapter.isEnabled()) {
// Request Bluetooth Adapter to be turned on
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
}
}
else
{
Log.i(DEBUG_TAG, "No bluetooth available");
}
Button launchReminderButton = (Button) findViewById(R.id.button);
launchReminderButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// Launch Reminder
// Used Context's startActivity() method
// Create an intent stating which Activity you would like to
// start
Intent reminder = new Intent(MainActivity.this, Reminder.class);
// Launch the Activity using the intent
startActivity(reminder);
}
}
);
}
#Override
public void onStart() {
super.onStart();
}
#Override
public void onResume() {
super.onResume();
// check for Bluetooth enabled on each resume
if(btAdapter != null && !btAdapter.isEnabled()){
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
}
}
#Override
public void onPause() {
super.onPause();
}
#Override
public void onStop() {
super.onStop();
}
#Override
public void onRestart() {
super.onRestart();
}
#Override
public void onDestroy() {
super.onDestroy();
btAdapter = null;
}
#Override
protected void onActivityResult(int request_enable_bt, int result_enable_bt, Intent data)
{
super.onActivityResult(request_enable_bt, result_enable_bt, data);
if(result_enable_bt == RESULT_OK) {
Toast.makeText(this, "Turned On", Toast.LENGTH_SHORT).show();
}
else if (result_enable_bt == RESULT_CANCELED)
{
Toast.makeText(this, "Didn't Turn On", Toast.LENGTH_SHORT).show();
finish();
}
}
Thanks.
Pay attention to the following code,the key is finish() you used here:
#Override
protected void onActivityResult(int request_enable_bt,
int result_enable_bt, Intent data)
{
super.onActivityResult(request_enable_bt, result_enable_bt, data);
if (result_enable_bt == RESULT_OK)
{
Toast.makeText(this, "Turned On", Toast.LENGTH_SHORT).show();
}
else if (result_enable_bt == RESULT_CANCELED)
{
Toast.makeText(this, "Didn't Turn On", Toast.LENGTH_SHORT).show();
finish();
}
}
When you start your app,the system will remind you to turn on your Bluetooth,because your request Bluetooth on in onCreate method.When you deny the request, and the method onActivityResult call back,you will run the following code:
else if (result_enable_bt == RESULT_CANCELED)
{
Toast.makeText(this, "Didn't Turn On", Toast.LENGTH_SHORT).show();
finish();
}
The finish() will finish your Activity,every time when you click your app,when you click deny first time,and then you click deny second time.Every time you got this: onCreate -> onResume.So you get the request to enable your Bluetooth twice!
I made an application with two activities. The first activity imports user parameters and the second activity sends data via bluetooth. I use .ACTION_REQUEST_ENABLE to enable bluetooth if it is disabled but when bt is closed my apk exits. It doesn't work. Any help?
I use this; code on create activity and after start handler and runnnable... I test it only findBT and work...
void findBT()
{
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if(mBluetoothAdapter == null)
{
myLabel.setText("No bluetooth adapter available");
}
if(!mBluetoothAdapter.isEnabled())
{
//My problem is there
Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBluetooth, 0);
}
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
if(pairedDevices.size() > 0)
{
for(BluetoothDevice device : pairedDevices)
{
if(device.getName().equals(strValue2))
{
mmDevice = device;
break;
}
}
}
myLabel.setText("Bluetooth Device Found");
}
here is the code :
public class AndroidBluetooth extends Activity {
private static final int REQUEST_ENABLE_BT = 1;
/** Called when the activity is first created. */
TextView stateBluetooth;
BluetoothAdapter bluetoothAdapter;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
stateBluetooth = (TextView)findViewById(R.id.bluetoothstate);
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
CheckBlueToothState();
}
private void CheckBlueToothState(){
if (bluetoothAdapter == null){
stateBluetooth.setText("Bluetooth NOT support");
}else{
if (bluetoothAdapter.isEnabled()){
if(bluetoothAdapter.isDiscovering()){
stateBluetooth.setText("Bluetooth is currently in device discovery process.");
}else{
stateBluetooth.setText("Bluetooth is Enabled.");
}
}else{
stateBluetooth.setText("Bluetooth is NOT Enabled!");
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
if(requestCode == REQUEST_ENABLE_BT){
CheckBlueToothState();
}
}
}
This code to check your device is BlueTooth enabled or not:
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
Toast.makeText(this.getParent(), ConfigClass.BLUETOOTH_NOT_SUPPORTED_ERROR, Toast.LENGTH_LONG);
}
Check and Enable your Bluetooth :
else if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, RESULT_OK);