Develop Reference

Non static inner class BroadcastReceiver not trigged

I have a BroadcastReceiver inside an Activity to change some views (when it's visible) from a service. I can't make it static(and declare it in manifest) because I access views from activity inside onReceive(), so I register/unregister it inside my Activity's onResume() & onPause().
public class MyActivity extends Activity {
private BroadcastReceiver mReceiver;
#Override
protected void onResume() {
super.onResume();
IntentFilter filter = new IntentFilter();
filter.addAction("action1");
filter.addAction("action2");
mReceiver = new CustomReceiver();
registerReceiver(mReceiver, filter);
}
#Override
protected void onPause() {
super.onPause();
if (mReceiver != null)
unregisterReceiver(mReceiver);
}
//some code
class MyBroadcast extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
//NEVER GET HERE
}
}
}
I send explicit intents (a must in Android O) to this receiver from a service like so:
Intent intent = new Intent(appContext, MyActivity.MyBroadcast.class);
intent.setAction("action1");
sendBroadcast(intent);
What is wrong with my implementation?
---SOLUTION---
As Mike M. commented we can use implicit intents to fire BroadcastReceiver even in Andorid O if they're registered using Context.registerReceiver()
Apps can use Context.registerReceiver() at runtime to register a receiver for any broadcast, whether implicit or explicit.
So it will be:
Intent intent = new Intent("action1");
sendBroadcast(intent);

Broadcast receiver in Fragment?

I use broadcast receiver, and in Fragment.java i register. But it's not working.
My code:
Intent intent = new Intent("android.intent.action.LOGIN");
intent.putExtra("message", obj.getToken());
intent.setAction("com.sunrise.android.LOGIN");
loginView.getContext().sendBroadcast(intent);
In Fragment:
#Override
public void onResume() {
super.onResume();
informationStudentPresenter = new InformationStudentPresenter(this);
IntentFilter intentFilter = new IntentFilter("android.intent.action.LOGIN");
getActivity().registerReceiver(broadcastReceiver, intentFilter);
}
private final BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(getActivity(), "CLGT", Toast.LENGTH_SHORT);
if(intent.getAction().equalsIgnoreCase("com.sunrise.android.LOGIN")){
if(!"".equals(findToken())) {
informationStudentPresenter.getProfileStudent();
informationStudentPresenter.showToast();
}
}
}
};
Could you tell me where my mistake and how to fix it?
Thanks.

You're changing the Intent's action name right after initializing it with a different name. Then you're registering the broadcast receiver with an IntentFilter that waits for the old action name.

Send/Receive Intents in the same class

Simple question, Is it possible to send/receive intents in the same class through LocalBroadcastReceiver? If yes can you show me an example?

Yes, LocalBroadcastReceiver works everywhere. Here's an example for an Activity:
BroadcastReceiver localBroadcastReciever = new BroadcastReceiver()
{
#Override
public void onReceive(Context context, Intent intent)
{
Log.d("BroadcastReceiver", "Message received " + intent.getAction());
}
};
#Override
protected void onStart()
{
super.onStart();
final LocalBroadcastManager localBroadcastManager =
LocalBroadcastManager.getInstance(this);
final IntentFilter localFilter = new IntentFilter();
localFilter.addAction("com.my.package.intent.ACTION_NAME_HERE");
localBroadcastManager.registerReceiver(localBroadcastReceiver, localFilter);
}
#Override
protected void onStop()
{
super.onStop();
final LocalBroadcastManager localBroadcastManager =
LocalBroadcastManager.getInstance(this);
// Make sure to unregister!!
localBroadcastManager.unregisterReceiver(localBroadcastReceiver);
}
Somewhere, either in the same Activity or elsewhere in your application (it doesn't matter):
final LocalBroadcastManager localBroadcastManager =
LocalBroadcastManager.getInstance(context);
localBroadcastManager.sendBroadcast(new Intent("com.my.package.intent.ACTION_NAME_HERE"));
You can, of course, use intent.putExtra to add any additional data or use multiple actions to differentiate broadcast messages.

Service to Activity communication

I am trying to update the UI (Activity) after some action has been performed in the service. This is very simple example but it doesn't seem to work for me. What am I missing here?
ExampleService:
public class ExampleService extends IntentService{
#Override
protected void onHandleIntent(Intent intent) {
notifyActivity();
}
private void notifyActivity() {
Intent broadcast = new Intent(this, ExampleActivity.class);
sendBroadcast(broadcast);
}
}
ExampleActivity:
public class ExampleActivity extends ListActivity {
private BroadcastReceiver receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(getApplicationContext(), "received", Toast.LENGTH_SHORT).show();
}
};
#Override
protected void onPause() {
super.onPause();
unregisterReceiver(receiver);
}
#Override
public void onResume() {
super.onResume();
IntentFilter filter = new IntentFilter();
registerReceiver(receiver, filter);
}
}

You cannot send a broadcast to an anonymous dynamic receiver that way. You will need to define an action string in the Intent and use that action string in the IntentFilter.
You might consider using LocalBroadcastManager for this scenario, for better performance. Here is a sample project demonstrating this.

Dynamically register/unregister a broadcast receiver in android

I want to dynamically register and unregister my receiver class with the broadcast:
"android.net.wifi.STATE_CHANGE"
This works very well if I do this in the manifest. But this makes it static. I want to do it dynamically in the activity class. What is its correspondent command in the activity class?
This is what my code is...
and I am getting a problem because of registering and unregistering(multiple times) my receiver(which is starting a service).
public class startScreen extends Activity {
/** Called when the activity is first created. */
private BroadcastReceiver receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Intent serviceIntent = new Intent();
serviceIntent.setAction("com.example.MyService");
context.startService(serviceIntent);
}
};
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.initial);
final IntentFilter filter = new IntentFilter();
filter.addAction("android.net.wifi.STATE_CHANGE");
Button button = (Button) findViewById(R.id.button1);
final ToggleButton toggleButton = (ToggleButton) findViewById(R.id.toggleButton1);
try {
...some code...
if (bool == true) {
toggleButton.setChecked(true);
this.registerReceiver(receiver, filter);
} else
toggleButton.setChecked(false);
} catch (Exception e) {
Log.e("Error", "Database", e);
} finally {
...
}
toggleButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
if ((toggleButton.isChecked())) {
getBaseContext().registerReceiver(receiver, filter);
} else {
if (receiver != null) {
getBaseContext().unregisterReceiver(receiver);
receiver = null;
}
}
}
});
}
#Override
protected void onResume() {
super.onResume();
if (bool == true) {
if (receiver == null)
this.registerReceiver(receiver, filter);
}
}
#Override
protected void onPause() {
super.onPause();
if (receiver != null) {
this.unregisterReceiver(receiver);
receiver = null;
}
}
}

The LocalBroadcastManager class is used to register for and send broadcasts of Intents to local objects within your process. This is faster and more secure as your events don't leave your application.
The following example shows an activity which registers for a customer event called my-event.
#Override
public void onResume() {
super.onResume();
// Register mMessageReceiver to receive messages.
LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,
new IntentFilter("my-event"));
}
// handler for received Intents for the "my-event" event
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// Extract data included in the Intent
String message = intent.getStringExtra("message");
Log.d("receiver", "Got message: " + message);
}
};
#Override
protected void onPause() {
// Unregister since the activity is not visible
LocalBroadcastManager.getInstance(this).unregisterReceiver(mMessageReceiver);
super.onPause();
}
// This method is assigned to button in the layout
// via the onClick property
public void onClick(View view) {
sendMessage();
}
// Send an Intent with an action named "my-event".
private void sendMessage() {
Intent intent = new Intent("my-event");
// add data
intent.putExtra("message", "data");
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
}

use the below methods to register/unregister your receiver:
registerReceiver(BroadcastReceiver receiver, new IntentFilter("android.net.wifi.STATE_CHANGE"));
unregisterReceiver(BroadcastReceiver receiver);
For reference have a look at this

Don't add dynamic broadcast receiver in onReceive on broadcast file. Add it on first activity or main activity of your application. If you needed it only when your application is open. But if you need it always received response just added it on manifest file
Register dynamic broadcast receiver on main activity
MyReceiver reciver;
#Override
protected void onResume() {
super.onResume();
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction("android.net.wifi.WIFI_STATE_CHANGED");
intentFilter.addAction("android.net.wifi.STATE_CHANGE");
reciver = new MyReceiver();
registerReceiver(reciver, intentFilter);
}
Unregister that broadcast receiver on activity stop or closed
#Override
protected void onStop() {
super.onStop();
unregisterReceiver(reciver);
}

Perhaps I'm a bit too late, but the problem lies on the fact that you are setting the receiver = null in your onPause method, and then never setting it again. You are also trying to register it in your onResume method but only if it is null, which makes no sense too.
You should change the logic where you set/test the null value of the receiver, to instead just use a boolean variable to keep track of the receiver status (if it's registered or not).

public void registerBroadcastReceiver(View view) {
this.registerReceiver(broadCastReceiver, new IntentFilter(
"android.intent.action.TIME_TICK"));
}
public void unregisterBroadcastReceiver(View view) {
this.unregisterReceiver(broadCastReceiver);
}