I know there are many SO posts related to this topic but none is working here.
I am doing sendBroadcast call from the class UserEntry.java: ---
final Intent intent = new Intent(DeviceScanActivity.ACTION_DISCONNECTED);
intent.putExtra(DeviceScanActivity.EXTRAS_DEVICE_NAME, bdDevice.getName());
intent.putExtra(DeviceScanActivity.EXTRAS_DEVICE_ADDRESS, bdDevice.getAddress());
getActivity().sendBroadcast(intent);
I have defined my broadcast receiver in class DeviceScanActivity.java: as ---
private final BroadcastReceiver mUpdateReceiver =
new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
device_name = intent.getExtras().getString(DeviceScanActivity.
EXTRAS_DEVICE_NAME);
device_address = intent.getExtras().getString(DeviceScanActivity.
EXTRAS_DEVICE_ADDRESS);
if (ACTION_CONNECTED.equals(action)) {
mConnected = "Connected";
invalidateOptionsMenu();
} else if (ACTION_DISCONNECTED.equals(action)) {
mConnected = "Disconnected";
invalidateOptionsMenu();
} else if (ACTION_CONNECTING.equals(action)) {
mConnected = "Connecting";
invalidateOptionsMenu();
}
else
{
mConnected = "";
invalidateOptionsMenu();
}
}
};
#Override
protected void onResume() {
super.onResume();
registerReceiver(mUpdateReceiver, makeUpdateIntentFilter());
}
#Override
protected void onPause() {
super.onPause();
unregisterReceiver(mUpdateReceiver);
}
So, user clicks connect button and sendBroadcast is called from class UserEntry then user switch to class DeviceScanActivity and still onReceive is never get called.
You are registering the BroadcastReceiver in DeviceScanActivity.java which means it won't be registered until DeviceScanActivity is active.
In other words the broadcast will simply get lost because there isn't a receiver available to receive the broadcast.
Related
I'm writing a service that must accept and react on ACTION_BATTERY_LOW broadcast. I'm using next code:
public class MyService extends Service {
...
private final BroadcastReceiver batteryBroadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Log.d(LOG_TAG, "batteryBroadcastReceiver.onReceive()->intent="+intent.toString());
if(intent.getAction().equals(Intent.ACTION_BATTERY_LOW))
Log.d(LOG_TAG, "intent.getAction() == Intent.ACTION_BATTERY_LOW!");
}
};
public void onCreate() {
super.onCreate();
final IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(Intent.ACTION_BATTERY_LOW);
registerReceiver(batteryBroadcastReceiver,intentFilter);
}
public void onDestroy() {
super.onDestroy();
unregisterReceiver(batteryBroadcastReceiver);
}
}
When battery charge level goes to low (~15%) Android sends an intent with action ACTION_BATTERY_LOW and then sends it again every 10 seconds which I'm receiving in MyServive. Why does it happen? What can I do or what I'm doing wrong? Tested on real device.
The period to send Intent.ACTION_BATTERY_LOW is up to the OS and the manufacturer. It's informed periodically so you have updated information through time and you can make better decisions.
I don't know what do you want to accomplish but if you are getting the action repeated you can monitor also Intent.ACTION_BATTERY_OKAY and have a flag indicating whether the action for the low battery has been made. That flag changes its value depending on the action the broadcastReceiver receives, e.g.
public class MyService extends Service {
...
private final BroadcastReceiver batteryBroadcastReceiver = new BroadcastReceiver() {
private bool mBatteryLowActionHasBeenMade = false;
#Override
public void onReceive(Context context, Intent intent) {
Log.d(LOG_TAG, "batteryBroadcastReceiver.onReceive()->intent="+intent.toString());
if(intent.getAction().equals(Intent.ACTION_BATTERY_LOW) && !this.mBatteryLowActionHasBeenMade ) {
Log.d(LOG_TAG, "intent.getAction() == Intent.ACTION_BATTERY_LOW!");
this.mBatteryLowActionHasBeenMade = true;
}
if(intent.getAction().equals(Intent.ACTION_BATTERY_OKAY)) {
this.mBatteryLowActionHasBeenMade = false;
}
}
};
public void onCreate() {
super.onCreate();
final IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(Intent.ACTION_BATTERY_LOW);
intentFilter.addAction(Intent.ACTION_BATTERY_OKAY);
registerReceiver(batteryBroadcastReceiver,intentFilter);
}
public void onDestroy() {
super.onDestroy();
unregisterReceiver(batteryBroadcastReceiver);
}
}
If that doesn't fit your requirements try monitoring the battery level with Intent.ACTION_BATTERY_CHANGED
I'm sending a progress value like int progress = 10 via Broadcast from IntentService to display the progress of uploading file.
protected void onHandleIntent(Intent intent) {
broadcastIntent = new Intent();
broadcastIntent.setAction(SendList.mReceiver.TEST);
try {
broadcastIntent.putExtra("Count",mArraylist.size());
[...uploading data...]
for (int i = 0; i < mArrayList.size(); i++) {
broadcastIntent.putExtra("progress", i);
sendBroadcast(broadcastIntent);
//...
}
}
So in my Activity I register the receiver but it is never called.
public class SendList extends Activity {
TextView textResult;
ProgressBar progressbar;
boolean mIsReceiverRegistered = false;
BroadcastReceiver receiver;
#Override
protected void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.sendlist);
textResult= (TextView)findViewById(R.id.maxFragments);
progressbar = (ProgressBar) findViewById(R.id.progressBar);
}
#Override
public void onResume() {
super.onResume();
if(!mIsReceiverRegistered) {
if (receiver == null)
receiver = new FragmentReceiver();
registerReceiver(receiver,new IntentFilter(mReceiver.TEST));
mIsReceiverRegistered = true;
}
}
#Override
public void onPause() {
super.onPause();
if(mIsReceiverRegistered) {
unregisterReceiver(receiver);
receiver = null;
mIsReceiverRegistered = false;
}
}
private void updateUI (Intent intent) {
progressbar.setProgress(intent.getIntExtra("progress", 0));
}
public class mReceiver extends BroadcastReceiver {
public static final String TEST = "upload";
#Override
public void onReceive(Context context, Intent intent) {
int count = intent.getIntExtra("Count",0);
progressbar.setMax(count);
textResult.setText(count);
updateUI(intent);
}
}
Where could be the problem? What am I doing wrong? Have I forgotten something?
Thanks for any help!
Kind Regards!
try to register you receiver as below -
IntentFilter filter = new IntentFilter();
filter.addAction(SendList.mReceiver.TEST);
registerReceiver(receiver,filter);
while broadcasting you are sending action as below
broadcastIntent.setAction(SendList.mReceiver.TEST);
and when you register it is different.
registerReceiver(receiver,new IntentFilter(FragmentReceiver.TEST));
Your action should be same while sending and receiving.
Hope this will help you.
I have a service and an activity. in service I broadcast messages received from network and in the activity show these messages. this works fine. but all messages will lost when the activity is in the background.
How can I get last messages(if exists) from server, in activity onResume(or onCreate)?
EDIT :
in service:
public class server extends Service implements Runnable
{
#Override
public void onCreate()
{
}
#Override
public IBinder onBind(Intent arg0)
{
return null;
}
#Override
public void onStart(Intent intent, int startID)
{
//initializing socket and begining listen
new Thread(this).start();
}
public void run()
{
String readed;
while (true)
{
if(reader == null) continue;
try
{
if ((readed = reader.readLine()) != null)
{
Intent intent = new Intent(SEND_DATA_INTENT);
intent.putExtra("type", "message");
intent.putExtra("content", readed.substring(1));
sendBroadcast(intent);
Thread.sleep(100);
}
}
catch (Exception ee) { }
}
}
}
and in activity:
public class menhaj extends Activity
{
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
#Override
protected void onResume()
{
if (dataUpdateReceiver == null) dataUpdateReceiver = new DataReciver();
IntentFilter intentFilter = new IntentFilter(server.SEND_DATA_INTENT);
registerReceiver(dataUpdateReceiver, intentFilter);
super.onResume();
};
#Override
protected void onPause()
{
if (dataUpdateReceiver != null) unregisterReceiver(dataUpdateReceiver);
super.onPause();
};
private class DataReciver extends BroadcastReceiver
{
#Override
public void onReceive(Context context, Intent intent)
{
if (intent.getAction().equals(server.SEND_DATA_INTENT))
{
Bundle bdl = intent.getExtras();
String type = bdl.getString("type");
if (type.equals("message"))
{
String message = bdl.getString("content");
db.addMessage(message);
showMessage(message);
}
}
}
}
}
If that activity is in the background, the user probably doesn't want to see messages from it. Show notifications from your services instead. Generally, an activity should de-register itself onPause() and register again onResume() when it comes back to the foreground.
I would declare BroadcastReceivers , those can receive messages and bring back to from your avtivity / app
I have an Android Activity that needs to catch two different broadcasts. My current approach is to have a single BroadcastReceiver within the Activity and catch both the broadcasts with it:
public class MyActivity extends Activity {
private MyActivity.BroadcastListener mBroadcastListener;
private boolean mIsActivityPaused = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mylayout);
// Create the broadcast listener and register the filters
mIsActivityPaused = false;
mBroadcastListener = new BroadcastListener();
IntentFilter filter = new IntentFilter();
filter.addAction(Params.INTENT_REFRESH);
filter.addAction(Params.INTENT_UPDATE);
registerReceiver(mBroadcastListener, filter);
}
#Override
protected void onResume() {
super.onResume();
mIsActivityPaused = false;
}
#Override
protected void onPause() {
super.onPause();
mIsActivityPaused = true;
}
#Override
protected void onDestroy() {
unregisterReceiver(mBroadcastListener);
super.onDestroy();
}
private void refresh() {
// refresh
}
private void update() {
// update
}
private class BroadcastListener extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Params.INTENT_REFRESH && !mIsActivityPaused)) {
refresh();
} else if (intent.getAction().equals(Params.INTENT_UPDATE)) {
update();
}
}
}
}
I want to execute refresh() only if my Activity is visible on the screen, but I want to catch INTENT_UPDATE and execute update() during the entire lifetime of the Activity, regardless of whether the Activity is visible or not.
I didn't find any way to unregister only one of the two filters that I register in onCreate, so I use a flag to enable or disable the action to be executed when the INTENT_REFRESH broadcast is caught, depending on the state of the Activity.
The question is: is this the correct approach?
Or, would it be better to have two separate BroadcastReceivers as follows:
public class MyActivity extends Activity {
private MyActivity.BroadcastListenerRefresh mBroadcastListenerRefresh;
private MyActivity.BroadcastListenerUpdate mBroadcastListenerUpdate;
private boolean mIsBroadcastListenerRefreshRegistered = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Create the broadcast listeners
mBroadcastListenerRefresh = new BroadcastListenerRefresh();
mBroadcastListenerUpdate = new BroadcastListenerUpdate();
registerReceiver(mBroadcastListenerRefresh, new IntentFilter(Params.INTENT_REFRESH));
registerReceiver(mBroadcastListenerUpdate, new IntentFilter(Params.INTENT_UPDATE));
}
#Override
protected void onResume() {
super.onResume();
if (mBroadcastListenerRefresh != null && !mIsBroadcastListenerRefreshRegistered) {
registerReceiver(mBroadcastListenerRefresh, new IntentFilter(Params.INTENT_REFRESH));
mIsBroadcastListenerRefreshRegistered = true;
}
}
#Override
protected void onPause() {
super.onPause();
if (mBroadcastListenerRefresh != null && mIsBroadcastListenerRefreshRegistered) {
unregisterReceiver(mBroadcastListenerRefresh);
mIsBroadcastListenerRefreshRegistered = false;
}
}
#Override
protected void onDestroy() {
unregisterReceiver(mBroadcastListenerRefresh);
unregisterReceiver(mBroadcastListenerUpdate);
super.onDestroy();
}
private void refresh() {
// refresh
}
private void update() {
// update
}
private class BroadcastListenerRefresh extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Params.INTENT_REFRESH)) {
refresh();
}
}
}
private class BroadcastListenerUpdate extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Params.INTENT_UPDATE)) {
update();
}
}
}
}
And which one has better performance?
instead, you may provide two different intent filters:
filter for refresh only
IntentFilter filterRefresh = new IntentFilter(Params.INTENT_REFRESH);
filter for refresh and update
IntentFilter filterRefreshUpdate = new IntentFilter();
filterRefreshUpdate.addAction(Params.INTENT_REFRESH);
filterRefreshUpdate.addAction(Params.INTENT_UPDATE);
now you may switch between intent filters by registering and un-registering the desired one but your receiver's implementation would be same
For every action , create IntentFilter and register it.
#Override
protected void onResume() {
super.onResume();
BroadcastListener receiver = new BroadcastListener();
// Register the filter for listening broadcast.
IntentFilter filterRefresh = new IntentFilter(Params.INTENT_REFRESH);
IntentFilter filterUpdate = new IntentFilter(Params.INTENT_UPDATE);
registerReceiver(receiver, filterRefresh);
registerReceiver(receiver, filterUpdate);
}
private class BroadcastListener extends BroadcastReceiver {
public void onReceive(Context ctx, Intent intent) {
if (intent.getAction().equals(Params.INTENT_UPDATE)) {
update();
} else if(intent.getAction().equals(Params.INTENT_REFRESH)) {
refresh();
}
}
}
Using KOTLIN you can do it inline:
broadcastReceiver = NukeBroadcastReceiver()
registerReceiver(broadcastReceiver, IntentFilter().apply {
addAction(ACTION_DESTROY_EVERYTHING)
addAction(ACTION_RESTART_WORLD)
})
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);
}