how to use android broadcast receiver - android

Here below is an example of service, activity and broadcast receiver. An activity is a setting that make changes to a service. The broadcast receiver listens to changes in settings and update service. learner2learner
public class xService extends Service {
#Override
public void onCreate() {
super.onCreate();
}
#Override
public IBinder onBind(Intent intent) {
return mBinder;
}
public static void setEnableNotification(int command) {
Log.i("EnableNotification","Updated");
if (command == 0)
enableNotification = true;
...
}
}
The method below is a part of an activity that sends broadcast:
#Override
protected void onCreate(Bundle savedInstanceState) {
....
IntentFilter filter = new IntentFilter();
filter.addAction(NotifyServiceReceiver.ACTION);
registerReceiver(receiver,filter);
}
final String ACTION="broadcast_settings";
public void onClick(View view) {
Intent intent = new Intent(ACTION);
switch (view.getId()) {
case R.id.switchNotification:
if(switchNotification.isChecked()==true)
{
intent.putExtra("EnableNotification", 0);
Log.i("Security365","Notification is enabled.");
}
else if ....
sendBroadcast(intent);
break;
}
The part below is my broadcast receiver:
public class xReceiver extends BroadcastReceiver {
final String ACTION="broadcast_settings";
#Override
public void onReceive(Context context, Intent intent) {
if(intent.getAction().equals(ACTION)){
int enableNotification = intent.getIntExtra("EnableNotification", 0);
if (enableNotification == 0)
Serurity365Service.setEnableNotification(0);
...
}
}
}
Mainfest
<receiver android:name=".xReceiver" android:enabled="true"></receiver>

If I understand your code correctly, the block
if(switchNotification.isChecked()==true)
{
intent.putExtra("EnableNotification", 1);
Log.i("Security365","Notification is enabled.");
}
is setting the EnableNotification to 1 in the intent used from sendBroadcast
In your broadcast receiver, you have
int enableNotification = intent
.getIntExtra("EnableNotification", 1);
if (enableNotification == 0)
Serurity365Service.setEnableNotification(0);
So it says to retrieve the extra EnableNotification and if no value, return the default value of 1 and then you never enter your if (enableNotification == 0) statement.
To be sure your broadcast receiver works correctly, add a log statement at the beginning of your receiver in the onReceive method.
EDIT:
Also the AndroidMANIFEST.xml has a tag <manifest> that declares a package.
For example
<manifest package="com.hello.world" ...
When you declare the receiver in the manifest, the . like in .xReceiver means that xReceiver.java should be located in the package com.hello.world.
If you have in a different package, specify the full name or relatiive to the package declared in <manifest
More info here

you are sending broadcast in a wrong way. You should send it as below:
public void onClick(View view) {
Intent intent = new Intent("your_action");
switch (view.getId()) {
case R.id.switchNotification:
if(switchNotification.isChecked()==true)
{
intent.putExtra("EnableNotification", 1);
Log.i("Security365","Notification is enabled.");
}
else if ....
sendBroadcast(intent);
break;
}
}
and receive it as:
public class xReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if(intent.getACtion().equals("your_action"){
int enableNotification = intent
.getIntExtra("EnableNotification", 1);
if (enableNotification == 0)
Serurity365Service.setEnableNotification(0);
...
}
}
}
update you Androidmanifest.xml too:
<receiver android:name=".xReceiver" android:enabled="true">
<intent-filter>
<action android:name="your_action" />
</intent-filter>
</receiver>

Related

How to launch an app when the screen unlocks?

I have tried this code but it's not working. Does anybody have any different solution? I have tried many ways like the below one from Stack Overflow but none of them is working.
manifest.xml
<receiver android:name=".ScreenReceiver">
<intent-filter>
<action android:name="android.intent.action.SCREEN_OFF"/>
<action android:name="android.intent.action.SCREEN_ON"/>
</intent-filter>
</receiver>
screenreceiver
public class ScreenReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Intent.ACTION_SCREEN_ON))
{
Intent intent = new Intent();
intent.setClass(context, ScreenLockActivity.class);
startActivity(intent);
}
}
}
To listen to screen on/off, your app should run by time and register Broadcast receiver to OS programmatically.
ScreenOnOffService.java
public class ScreenOnOffService extends Service {
public IBinder onBind(Intent intent) {
return null;
}
public void onCreate() {
super.onCreate();
Log.i("ScreenOnOffService", "onCreate: ");
IntentFilter intentFilter = new IntentFilter();
// intentFilter.addAction("android.intent.action.SCREEN_OFF");
intentFilter.addAction("android.intent.action.SCREEN_ON");
registerReceiver(ScreenOnReceiver.newInstance(), intentFilter);
}
public void onDestroy() {
super.onDestroy();
Log.i("ScreenOnOffService", "onDestroy: ");
unregisterReceiver(ScreenOnReceiver.newInstance());
// startService(new Intent(this,ScreenOnOffService.class));
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return Service.START_STICKY;
}
}
ScreenOnReceiver.java
public class ScreenOnReceiver extends BroadcastReceiver {
public static final String TAG = "ScreenOn";
public static volatile ScreenOnReceiver screenOn;
public static ScreenOnReceiver newInstance() {
if (screenOn == null) {
screenOn = new ScreenOnReceiver();
}
return screenOn;
}
#Override
public void onReceive(Context context, Intent intent) {
Log.i("hieuN", "intent: " + intent.getAction());
// do work. start activity.
}
}
Start service in activity
Intent service = new Intent(this, ScreenOnOffService.class);
startService(service);

BroadcastReceiver does not receive intent Intent.ACTION_LOCALE_CHANGED

I want my app to be aware anytime the user changes the locale. So in my Application class, I create a receiver to listen to the system intent ACTION_LOCALE_CHANGED:
public final class MyApp extends Application {
private BroadcastReceiver myReceiver = new BroadcastReceiver() {
#Override public void onReceive(Context context, Intent intent) {
String locale = Locale.getDefault().getCountry();
Toast.makeText(context, "LOCALE CHANGED to " + locale, Toast.LENGTH_LONG).show();
}
};
#Override public void onCreate() {
IntentFilter filter = new IntentFilter(Intent.ACTION_LOCALE_CHANGED);
LocalBroadcastManager.getInstance(this).registerReceiver(myReceiver, filter);
}
}
When I press home and go to the settings app to change my locale, the Toast is not shown. Setting the breakpoint inside onReceive shows it never gets hit.
Why do you want the BroadcastReceiver in Application class. My suggestion is to have a separate class for BroadcastRecevier.
public class LocaleChangedReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction (). compareTo (Intent.ACTION_LOCALE_CHANGED) == 0)
{
Log.v("LocaleChangedRecevier", "received ACTION_LOCALE_CHANGED");
}
}
}
and register your Brodcast receiver in Manifest file.
<receiver
android:name=".LocaleChangedReceiver"
android:enabled="true"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.LOCALE_CHANGED" />
</intent-filter>
</receiver>
Intent.ACTION_LOCALE_CHANGED is not a local broadcast, so it won't work when you register it with LocalBroadcastManager. LocalBroadcastManager is used for the broadcast used inside your app.
public class MyApp extends Application {
private BroadcastReceiver myReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String locale = Locale.getDefault().getCountry();
Toast.makeText(context, "LOCALE CHANGED to " + locale,
Toast.LENGTH_LONG).show();
}
};
#Override
public void onCreate() {
super.onCreate();
IntentFilter filter = new IntentFilter(Intent.ACTION_LOCALE_CHANGED);
registerReceiver(myReceiver, filter);
}
}

LocalBroadcastManager not working

I'm trying to sendMessage from service to activity, but for some reason it's not working.
Activity
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_barcode);
LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,
new IntentFilter("custom-event-name"));
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// Get extra data included in the Intent
Boolean state = intent.getBooleanExtra("state",false);
if(state){
Toast.makeText(getApplicationContext(),"Данные успешно отправлены",Toast.LENGTH_SHORT).show();
}
}
};
#Override
protected void onDestroy() {
// Unregister since the activity is about to be closed.
LocalBroadcastManager.getInstance(this).unregisterReceiver(mMessageReceiver);
super.onDestroy();
}
Service
private void sendMessage(boolean state) {
Log.d("sender", "Broadcasting message");
Intent intent = new Intent("custom-event-name");
// You can also include some extra data.
intent.putExtra("state", state);
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
}
Log.d "broadcasting message" is shown and then nothing happens
PROBLEM SOLVED
In android manifest
<service
android:name=".service.TerminalService"
android:process=":update_service" >
</service>
It seems when android:process is specified localbroadcastmanager is not working. I just deleted android:process line and it worked
Nothing wrong with your code .only update your receive method else clause
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// Get extra data included in the Intent
Boolean state = intent.getBooleanExtra("state",false);
if(state){
Toast.makeText(getApplicationContext(),"Данные успешно отправлены",Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(getApplicationContext(),"else message ",Toast.LENGTH_SHORT).show();
}
}
};
com.android.support:localbroadcastmanager -> change
androidx.localbroadcastmanager:localbroadcastmanager:1.0.0

IS there any way to open our app in android when anyone unlocks the screen

i want to open my app every time when user unlocks it home screen.Please help me this app is only for my personal use so any help will be great
thanks
Register your application to receive the SCREEN_ON intent by registering a receiver in your manifest:
<receiver android:name=".receiverScreenUnlocked" >
<intent-filter>
<action android:name="android.intent.action.SCREEN_ON" />
</intent-filter>
</receiver>
</application>
Write the receiver class to receive an intent when user unloks the screen and run the activity you want:
public class receiverScreenUnlocked extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent)
{
Intent i = new Intent();
i.setClassName("com.test", "com.test.MainActivity");
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);
}
}
*
public class ScreenReceiver extends BroadcastReceiver {
public static boolean wasScreenOn = true;
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
// DO WHATEVER YOU NEED TO DO HERE
wasScreenOn = false;
} else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
// AND DO WHATEVER YOU NEED TO DO HERE
wasScreenOn = true;
}
}
}
Example
public class ExampleActivity extends Activity {
#Override
protected void onCreate() {
// INITIALIZE RECEIVER
IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
BroadcastReceiver mReceiver = new ScreenReceiver();
registerReceiver(mReceiver, filter);
// YOUR CODE
}
#Override
protected void onPause() {
// WHEN THE SCREEN IS ABOUT TO TURN OFF
if (ScreenReceiver.wasScreenOn) {
// THIS IS THE CASE WHEN ONPAUSE() IS CALLED BY THE SYSTEM DUE TO A SCREEN STATE CHANGE
System.out.println("SCREEN TURNED OFF");
} else {
// THIS IS WHEN ONPAUSE() IS CALLED WHEN THE SCREEN STATE HAS NOT CHANGED
}
super.onPause();
}
#Override
protected void onResume() {
// ONLY WHEN SCREEN TURNS ON
if (!ScreenReceiver.wasScreenOn) {
// THIS IS WHEN ONRESUME() IS CALLED DUE TO A SCREEN STATE CHANGE
System.out.println("SCREEN TURNED ON");
} else {
// THIS IS WHEN ONRESUME() IS CALLED WHEN THE SCREEN STATE HAS NOT CHANGED
}
super.onResume();
}
}
Reference

run app in background without activity alerts user when Contact or sms is deleted

i want to make my app to be run in background and listens for
contact,sms deletion events.
for that i created a service in my app but i dnt how to start without activity
my code is like this
public class DeleteService extends Service {
ContentResolver cr;
MyContentObserver observer=new MyContentObserver();
#Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return mBinder;
}
#Override
public void onCreate() {
cpath=ContactsContract.Contacts.CONTENT_URI;
// some action
}
#Override
public void onDestroy() {
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// TODO Launch a background thread to do processing.
super.onStartCommand(intent, flags, startId);
cpath=ContactsContract.Contacts.CONTENT_URI;
cr=getContentResolver();
cur=cr.query(cpath, null, null, null, null);
this.getApplicationContext().getContentResolver().registerContentObserver(cpath, true, observer);
return Service.START_STICKY;
}
private class MyContentObserver extends ContentObserver {
public MyContentObserver() {
super(null);
}
#Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
nfm=(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
int NOTIFICATION_ID = 1;
Intent intent1 = new Intent();
PendingIntent pi = PendingIntent.getActivity(DeleteService.this, 1, intent1, 0);
nf=new Notification(R.drawable.ic_launcher,"Contact Database changed",System.currentTimeMillis());
nf.setLatestEventInfo(getApplicationContext(), "Delete Event", "contact name", pi);
nf.flags = nf.flags |
Notification.FLAG_ONGOING_EVENT;
}
#Override
public boolean deliverSelfNotifications()
{
super.deliverSelfNotifications();
return true;
}
}
public class LocalBinder extends Binder {
DeleteService getService() {
return DeleteService.this;
}
}
}
register ACTION_SCREEN_ON or ACTION_USER_PRESENT broadcast recivers for your Appliction in Service and start Service when screen is on or user is present. you can register ACTION_SCREEN_OFF broadcast reciver for stoping Service when phone screen is off to avoid battery drain by your app.as:
In manifest.xml:
<receiver android:name="com.my.AppStart">
<intent-filter>
<action android:name="android.intent.action.SCREEN_ON" />
<action android:name="android.intent.action.SCREEN_OFF" />
<action android:name="android.intent.action.USER_PRESENT" />
</intent-filter>
</receiver>
BroadcastReceiver :
public class AppStart extends BroadcastReceiver {
public static final String present = "android.intent.action.USER_PRESENT";
public static final String screenon = "android.intent.action.SCREEN_ON";
public static final String screenoff = "android.intent.action.SCREEN_OFF";
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(present) || intent.getAction().equals(screenon) )
{
Intent i=new Intent(context,DeleteService.class);
context.startService(i);
}
if (intent.getAction().equals(screenoff))
{
//STOP YOUR SERVICE HERE
}
}
}
A service can only by started by an Activity, or a BroadCast receiver, or a service which is already started. It can't be stand-alone(It can't start by itself). So, you would need one of the two components to start it. you can make an activity which starts the service which is the preferred way. But if you don't want to provide a user interface, implement a broadcast receiver which fires up when the phone is switched on and the boot up is completed, Inside that br, start your service. This will also help you run the service as soon as a phone starts.
for example in your manifest:
<receiver android:name="com.my.MyBroadcastReceiver">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
and in the br:
public class MyBroadcastReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Intent i=new Intent(context,DeleteService.class);
context.startService(i);
}
}
In your activity .. put this code in oncreate
Intent svc=new Intent(youractivity.this,DeleteService.class);
startService(svc);

Categories

Resources