Develop Reference

Broadcast not triggered when process is created

I have a broadcast which monitors for unlock event for the phone. But when the app's process is killed and no longer in memory, Unlocking the phone does not trigger the Receiver, instead I can see in the Android studio, that new process is created for that app.
If lock and unlock it again, then as the process is already running, I can see the BroadcastReceiver is triggered.
<receiver
android:name=".UserPresentBroadcastReceiver"
android:enabled="true"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.USER_PRESENT" />
</intent-filter>
</receiver>
Broadcast Receiver:
public class UserPresentBroadcastReceiver extends BroadcastReceiver {
private static final String TAG = UserPresentBroadcastReceiver.class.getSimpleName();
#Override
public void onReceive(Context arg0, Intent intent) {
Log.d(TAG, "onReceive: Unlock Boradcast received");
if (intent.getAction().equals(Intent.ACTION_USER_PRESENT)) {
Toast.makeText(arg0, "You just unlocked the device", Toast.LENGTH_LONG).show();
}
}
}
I am unable to understand this behavior. Is this the default behavior?

You have to register and unregister this broadcast receiver in Activity(or Service for listening in background all the time).
Manifest entry won't work.

Listen for screen power on / power off even after onDestroy()

I am trying to listen for screen power on / power off in my app but after onDestroy() since the app is destroyed its stops listening is there any way for my app to continue listening after it shuts down like a background process?
BroadcastReceiver class:
public class ScreenReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent i) {
if (i.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
System.out.println("Screen turned off");
} else if(i.getAction().equals(Intent.ACTION_SCREEN_ON)) {
System.out.println("Screen turned on");
}
}
}
i put this code in my onCreate() in my main activity
IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
BroadcastReceiver mReceiver = new ScreenReceiver();
registerReceiver(mReceiver, filter);

If you register your ScreenReceiver in your AndroidManifest, you'll get the broadcast even if your app has been destroyed. The only time you won't get the broadcast is if the user force stops the app through settings
something like
<receiver android:name=".ScreenReceiver">
<intent-filter>
<action android:name="action_looking_for"/>
</intent-filter>
</receiver>

how to use broadcast receiver on receive

i have a project and when i run the application,one service should be active and when the device is turned on,my android service should be active.
The project runs in emulator successfully but in my phone when i turn on the device it doesn't works!
my broadcast receiver :
public class BroadcastReceiverOnTurnedOn extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Intent startServiceIntent = new Intent(context, MyService.class);
context.startService(startServiceIntent);
}
}
i added :
<receiver android:name="com.dariran.BroadcastReceiverOnTurnedOn">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
to appliation tag on Manifest.xml and
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

You are registering a BroadcastReceiver not a Service. Services will generally run in the background all of the time (if memory and resources permit).
Your broadcast receiver activates only when the device is rebooted - and your emulator "boots" every time you start it up. Your phone does not "boot" when the app is installed.
You should either register for events like "app installed" or else actually implement a service, like here:
http://www.vogella.com/tutorials/AndroidServices/article.html

You need to make sure that once you install the app on device it should be started once by clicking app icon then only boot receiver will receive boot event on subsequent reboots calls.

i undrestand that if i install app in internal storage in works successfully even device rebooted but when i install the app on external storage and then reboot device it not work
i have a project that when run application one service be active and when device be turn on my android service be active. the project run in device's internal memory successfully but when i install it on external memory and reboot my device again don't work!
for first i call my service in first acitivity and it works, but when i reboot my device it doesn't work !
my activity :
public class FirstClass extends Activity
{
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.first);
final Handler handler = new Handler();
handler.postDelayed(new Runnable()
{
public void run()
{
startService(new Intent(getApplicationContext(), MyService.class));
startActivity(new Intent(FirstClass.this, MainActivity.class));
finish();
}
},5000);
}
/////////////////////////////////////////////////
}
my broadcast receiver :
public class BroadcastReceiverOnTurnedOn extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Intent startServiceIntent = new Intent(context, MyService.class);
context.startService(startServiceIntent);
}
}
i added :
<service
android:name="com.dariran.MyService"
android:enabled="true"
android:exported="true" >
</service>
<receiver android:name="com.dariran.BroadcastReceiverOnTurnedOn"
android:enabled="true">
<intent-filter android:priority="1">
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE" />
</intent-filter>
</receiver>to appliation tag on Manifest.xml and
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
i added this code to my service class to put a filter to recognize the external storage but don't work again :(
#Override
public void onStart(Intent intent, int startId) {
try {
IntentFilter filter = new IntentFilter(Intent.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE);
filter.addAction(Intent.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE);
BroadcastReceiver mReceiver = new BroadcastReceiverOnTurnedOn();
registerReceiver(mReceiver, filter);
} catch (Exception e) {
}
}

Screen_Off does not work in Application Level

Screen_Off does not work in application Level ,although it is working on Activity Level.
My Problem,when Screen goes off,it must go to Login screen,below code ,successfully go to Login screen but it cause me unregistered Receive Broadcast
what i have did
if l do in Menifesty level,Screen off broadcast does not fire,
Manifest Level
<receiver android:name="com.android.libray.ScreenReciver" android:enabled="true" >
<intent-filter>
<action android:name="android.intent.action.SCREEN_OFF"/>
<action android:name="android.intent.action.SCREEN_ON"/>
</intent-filter>
</receiver>
if i do in activity level,then it will fire screenReciver
IntentFilter filter =new IntentFilter(Intent.ACTION_SCREEN_OFF);
BroadcastReceiver mReceiver=new ScreenReciver();
registerReceiver(mReceiver, filter);
public class ScreenReciver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
// do whatever you need to do here
Intent myintent = new Intent(context,TimerClockActivity.class);
myintent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
myintent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(myintent);
wasScreenOn = false;
Log.v("screenoff", "Logggoff");
} else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
// and do whatever you need to do here
}
}
}

The SCREEN_OFF Broadcast is a protected broadcast, and you will only receive it if you register dynamically through Java code in a Service or Activity or another Receiver. Registering in the manifest doesn't work for this broadcast.

ACTION_SCREEN_ON and ACTION_SCREEN_OFF not working?

I'm trying to turn WiFi off when the screen is OFF (locked), and turn it on again when screen is ON (unlocked).
I made a BroadcastReceiver; put in manifest this code:
<receiver android:name="MyIntentReceiver">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
<action android:name="android.intent.action.SCREEN_OFF" />
<action android:name="android.intent.action.SCREEN_ON" />
<action android:name="android.intent.action.USER_PRESENT" />
<category android:name="android.intent.category.HOME" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</receiver>
and this is the class MyIntentReceiver:
package org.androidpeople.boot;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
public class MyIntentReceiver extends BroadcastReceiver {
// Called when boot completes
public static boolean startup;
#Override
public void onReceive(Context context, Intent intent) {
// Set what activity should launch after boot completes
System.out.println("Intent Action: " + intent.getAction());
if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
System.out.println("locked : ACTION_SCREEN_OFF");
} else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
System.out.println("not locked : ACTION_SCREEN_ON ");
} else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
System.out.println("User Unlocking it ");
}
else if (intent.getAction().equals(Intent.ACTION_BOOT_COMPLETED)) {
// this to indicate that program is running
// automaticlly not manually by user
startup = true;
System.out.println("Automatic BOOT at StartUp");
Intent startupBootIntent = new Intent(context, LaunchActivity.class);
startupBootIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(startupBootIntent);
}
}
}
And the result is - both ACTION_SCREEN_ON
and ACTION_SCREEN_OFF never fired!
USER_PRESENT and BOOT_COMPLETED worked fine but the other did not. I'm using an emulator, not a real device - can this cause the problem?
Any help?
I need to catch the screen on and off in order to enable/disable WiFi
to save battery.
Thanks in advance

To capture the SCREEN_OFF and SCREEN_ON actions (and maybe others) you have to configure the BroadcastReceiver by code, not through the manifest.
IntentFilter intentFilter = new IntentFilter(Intent.ACTION_SCREEN_ON);
intentFilter.addAction(Intent.ACTION_SCREEN_OFF);
BroadcastReceiver mReceiver = new ScreenStateBroadcastReceiver();
registerReceiver(mReceiver, intentFilter);
It's tested and works right.

You cannot catch those intents through XML (I forget why). However, you could use a Service that registers a BroadcastReceiver member in its onStartCommand() and unregisters it in its onDestroy(). This would require the service to be running in the background, constantly or as long as you need it to, so be sure to explore alternative routes.
You could define the BroadcastReceiver in your Service class like so:
private final class ScreenReceiver extends BroadcastReceiver {
#Override
public void onReceive(final Context context, final Intent intent) {
if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
//stuff
} else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
//other stuff
}
}
}
For a slightly complicated example, but one that shows how the BroadcastReceiver and Service interact see CheckForScreenBugAccelerometerService from my app, ElectricSleep.