Develop Reference

Call method when Application Closes

I know this is asked many times, but I want to clear things up
In which activity should I place onDestroy()? Say I am in the MainActivity A and I move to activity B. But then I close the application while being on activity B. Does the onDestroy() method in MainActivity A get called? Or should I put an onDestroy() method for every activity in the application? Or is there any other way around this?
I have tried reading documentation and reading other answers but they don't help me clearly.

There are multiple ways to do so , Here I have mentioned the most reliable way I have found during development carrier . You need to create a Service which can keep an eye whether application got closed or not, so here I have mentioned the code !
1.Create Service , as you can see below there is a new class named as MyService, this needs to extended to Service.
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;
import androidx.annotation.Nullable;
public class MyService extends Service {
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return START_STICKY;
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onTaskRemoved(Intent rootIntent) {
Log.d(getClass().getName(), "App just got removed from Recents!");
}
}
2.Add this entry to Manifest.xml as below ...
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
>
<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/Theme.TestApplication">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".MyService" />
</application>
</manifest>
3.This is Just a Service that will run in background , but we need to start it once the application starts , so in your launcher activity start it like below.
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent stickyService = new Intent(this, MyService.class);
startService(stickyService);
}
}
4.Service will start and whenever User will Swipe out the application from recent , the function onTaskRemoved will be called automatically , in this function you can put your required work or code to be executed at the application end !

How to Pass Data From a BroadcastReceiver to an Activity in Android

I am working on my first Android app, which is a paging device. It will intercept a SMS message from a certain number with a certain content in it, display that and then allow the user to send a pre-defined reply back to that same number. I have gathered up code snippets from numerous sources (including stackoverflow of course) but I haven't yet got it working.
My file structure is as shown here
The part I am struggling with is SmsBroadcastReceiver and ReceiveAlert, which should display the content of the SMS and has a button to initiate the reply.
SmsBroadcastReceiver.java looks like this:
package com.example.alert6;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.provider.Telephony;
import android.telephony.SmsMessage;
public class SmsBroadcastReceiver extends BroadcastReceiver {
public static final String EXTRA_MESSAGE = "com.example.alert6.MESSAGE";
#Override
public void onReceive(Context context, Intent intent) {
String smsSender = "";
String smsBody = "";
for (SmsMessage smsMessage : Telephony.Sms.Intents.getMessagesFromIntent(intent)) {
smsSender = smsMessage.getOriginatingAddress();
smsBody = smsMessage.getMessageBody();
}
if (smsSender.equals("+420775367297")) {
if (smsBody.contains("Test")) {
intent.putExtra(EXTRA_MESSAGE, smsBody);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); // adding this flag starts the new Activity in a new Task
context.startActivity();
}
}
}
}
ReceiveAlertActivity.java is this:
package com.example.alert6;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
public class ReceiveAlertActivity extends AppCompatActivity {
private static final int SMS_PERMISSION_CODE = 101;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_receive_alert);
}
// Get the Intent that started this activity and extract the string
Intent intent = getIntent();
String taskingalert = intent.getStringExtra(SmsBroadcastReceiver.EXTRA_MESSAGE);
// Capture the layout's TextView and set the string as its text
TextView receivedAlert = findViewById(R.id.receivedAlert);
receivedAlert.setText(taskingalert);
public boolean respond(View view) {
if (!hasReadSmsPermission()) {
requestReadAndSendSmsPermission();
return false;
}
Intent intent = new Intent(this, SendResponseActivity.class);
startActivity(intent);
return false;
}
/**
* Runtime permission shenanigans
*/
private boolean hasReadSmsPermission() {
return (ContextCompat.checkSelfPermission(ReceiveAlertActivity.this,
Manifest.permission.READ_SMS) == PackageManager.PERMISSION_GRANTED) &&
(ContextCompat.checkSelfPermission(ReceiveAlertActivity.this,
Manifest.permission.RECEIVE_SMS) == PackageManager.PERMISSION_GRANTED) &&
(ContextCompat.checkSelfPermission(ReceiveAlertActivity.this,
Manifest.permission.SEND_SMS) == PackageManager.PERMISSION_GRANTED);
}
private void requestReadAndSendSmsPermission() {
ActivityCompat.requestPermissions(ReceiveAlertActivity.this, new String[]{Manifest.permission.READ_SMS, Manifest.permission.RECEIVE_SMS, Manifest.permission.SEND_SMS},
SMS_PERMISSION_CODE);
}
}
And the manifest is this:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.example.alert6">
<uses-permission android:name="android.permission.RECEIVE_SMS" />
<uses-permission android:name="android.permission.READ_SMS" />
<uses-permission android:name="android.permission.SEND_SMS" />
<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/Theme.Alert6">
<activity
android:name=".SendResponseActivity"
android:parentActivityName=".ReceiveAlertActivity">
</activity>
<activity
android:name=".ReceiveAlertActivity"
android:parentActivityName=".MainActivity">
</activity>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver
android:name=".SmsBroadcastReceiver"
android:enabled="true"
android:exported="true"
tools:ignore="Instantiatable">
<intent-filter android:priority="999" >
<action android:name="android.provider.Telephony.SMS_RECEIVED" />
</intent-filter>
</receiver>
</application>
</manifest>
Android Studio is showing errors in SmsBroadcastReceiver and ReceiveAlertActivity but not giving enough information to resolve them.
In SmsBroadcastReceiver, it tells me it cannot resolve method 'startActivity()'. Something needs to go in the brackets, but what?
In ReceiveAlertActivity the problems revolve around receivedalert and taskingalert. It cannot resolve setText because taskingalert is an unknown class. Obviously it's not a class, it's a string so I'm doing something wrong, but what?
Sorting out these problems may not be the end. At the moment I can't test if the app works because the build fails due to the above. Then if I get this lot working, I have some other challenges, like waking up the screen and playing a sound the broadcast receiver is triggered, and stopping the sound when the button is pressed.

You can use an Observable object in your BroadcastReceiver to store the piece of information you want to send and implement the Observer interface in your Activity so that it will be warned of every change occuring to the Observable object.

Android Studio Wear Os application can't be installed INSTALL_PARSE_FAILED_NO_CERTIFICATES

I'm new in the the magic world of Android Studio. I'm trying to develop a simple Wear Os application to scan the near Bluetooth devices.
MainActivity.java
package com.firstapp.testble;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.wearable.activity.WearableActivity;
import android.util.Log;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.util.ArrayList;
public class MainActivity extends WearableActivity {
private ListView listView;
private ArrayList<String> mDeviceList = new ArrayList<String>();
private BluetoothAdapter mBluetoothAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.listView);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if(mBluetoothAdapter == null){
System.out.println(">>>>>>>>>>>>>>>>>>ERRORRE");
}else{
mBluetoothAdapter.startDiscovery();
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter);
// Enables Always-on
setAmbientEnabled();
}
}
#Override
protected void onDestroy() {
unregisterReceiver(mReceiver);
super.onDestroy();
}
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = intent
.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
mDeviceList.add(device.getName() + "\n" + device.getAddress());
Log.i("BT", device.getName() + "\n" + device.getAddress());
listView.setAdapter(new ArrayAdapter<String>(context,
android.R.layout.simple_list_item_1, mDeviceList));
}
}
};
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.firstapp.testble">
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-feature android:name="android.hardware.type.watch" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#android:style/Theme.DeviceDefault">
<uses-library
android:name="com.google.android.wearable"
android:required="true" />
<!--
Set to true if your app is Standalone, that is, it does not require the handheld
app to run.
-->
<meta-data
android:name="com.google.android.wearable.standalone"
android:value="true" />
<activity
android:name=".MainActivity"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
When I'm trying to debug the application in my Fossil SmartWatch uploading the APK to the device, i receive the following error:
Launching 'app' on Physical Device.
Timed out waiting for process (com.firstapp.testble) to appear on fossil-garrett_hr-127.0.0.1:4444.
Installation did not succeed.
The application could not be installed: INSTALL_PARSE_FAILED_NO_CERTIFICATES
List of apks:
[0] 'C:\Users\marac\AndroidStudioProjects\TestBLE\app\build\outputs\apk\debug\app-debug.apk'
APK signature verification failed.
With other simple application I don't have this kind of problem.
Here what I already tryed:
Build> Generate Singned Bundle / APK
Clean Project and Rebuild Project
File > Invalidate Cache / Restart
Disconnect and reconnect the smartwatch
Re-Install Android Studio
I don't understand why I have this problem and why I have it only with this project. Can you help me to solve?
Thanks,
Mara

If you have signed your apk, you might consider install the release build instead of the debug build that you are trying to install.
From the following log, I can see that you are trying to install the debug build.
[0] 'C:\Users\marac\AndroidStudioProjects\TestBLE\app\build\outputs\apk\debug\app-debug.apk'
The release apk can be found under \Users\marac\AndroidStudioProjects\TestBLE\app\build\outputs\apk\release folder.

How to Listen for Bluetooth Headset Buttons in an Android App?

What is the proper way to handle Bluetooth media buttons in an Android app? At this point, all I want is an event to fire when I press the pause/play button on my Bluetooth headset. Somehow, I had a working solution yesterday, and today it just doesn't work. Without reinstalling the app, or any update happening on my phone, the onReceive method of my subclass of BroadcastReceiver is never entered. I'm targeting Android 9.0, since this is just for myself.
I used the information in these two questions for the solution:
How to capture key events from bluetooth headset with android
BroadcastReceiver for ACTION_MEDIA_BUTTON not working
This is a bare minimum version of what was working yesterday, which currently does not work:
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.example.myapplication">
<uses-permission android:name="android.permission.BLUETOOTH" />
<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"
tools:ignore="GoogleAppIndexingWarning">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver android:name=".MediaButtonIntentReceiver">
<intent-filter android:priority="2139999999">
<action android:name="android.intent.action.MEDIA_BUTTON" />
</intent-filter>
</receiver>
</application>
</manifest>
MainActivity.java
package com.example.myapplication;
import androidx.appcompat.app.AppCompatActivity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.media.AudioManager;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
MediaButtonIntentReceiver mMediaButtonReceiver = new MediaButtonIntentReceiver();
IntentFilter mediaFilter = new IntentFilter(Intent.ACTION_MEDIA_BUTTON);
AudioManager mAudioManager = null;
ComponentName mReceiverComponent = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
mReceiverComponent = new ComponentName(this, MediaButtonIntentReceiver.class);
mediaFilter.setPriority(2139999999);
registerReceiver(mMediaButtonReceiver, mediaFilter);
}
}
MediaButtonIntentReceiver.java
package com.example.myapplication;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
public class MediaButtonIntentReceiver extends BroadcastReceiver {
public MediaButtonIntentReceiver() {
super();
Log.i("mylog", "init");
}
#Override
public void onReceive(Context context, Intent intent) {
Log.i("mylog", "receive");
abortBroadcast();
}
}

Boot Receiver doesn't work

First off, please don't mark this as duplicate, I have tried to resolve the issue using several different questions here on SO, and tried each and every solution for this issue, over SO.
Therefore, I reproduce my entire code here along with the logcat.
The Issue:
I am trying to write an application that will boot up on reboot of a device.
I can see several applications receiving the BOOT_COMPLETED action in the logcat, but I can't see my application anywhere in logcat on device reboot.
Point to Note:
I have already launched my app once before testing through Device Reboot.
Code Files:
AndroidManifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.xyz.abc"
android:versionCode="1"
android:versionName="1.0" >
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<receiver android:name="com.xyz.abc.autostart" android:enabled="true" android:exported="true">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</receiver>
<activity
android:name=".hello"
android:label="#string/title_activity_hello" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service
android:name=".service"
android:enabled="true" />
</application>
</manifest>
Autostart.java
package com.xyz.abc;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
/**
* Created by admin on 008, 8 May 2015.
*/
public class autostart extends BroadcastReceiver
{
public void onReceive(Context context, Intent arg1)
{
Log.w("boot_broadcast_poc", "starting service...");
context.startService(new Intent(context, service.class));
}
}
service.java
package com.xyz.abc;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;
/**
* Created by admin on 008, 8 May 2015.
*/
public class service extends Service
{
private static final String TAG = "MyService";
#Override
public IBinder onBind(Intent intent) {
return null;
}
public void onDestroy() {
Toast.makeText(this, "My Service Stopped", Toast.LENGTH_LONG).show();
Log.d(TAG, "onDestroy");
}
#Override
public int onStartCommand(Intent pIntent, int flags, int startId) {
// TODO Auto-generated method stub
Toast.makeText(this, "NotifyingDailyService", Toast.LENGTH_LONG).show();
Log.i("bootbroadcastpoc","NotifyingDailyService");
return super.onStartCommand(pIntent, flags, startId);
}
}
hello.java
package com.xyz.abc;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;
public class hello extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_hello);
Toast.makeText(getBaseContext(), "Hello........", Toast.LENGTH_LONG).show();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_hello, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
Finally, the logcat filtered by BOOT_COMPLETED:
UPDATE : Removed the logcat as it was not necessary
(Also I have found the solution which I will have posted down shortly).
logcat filtered for "boot_broadcast_poc" is blank.
logcat filtered for "bootbroadcastpoc" is blank.
I definitely don't see the service started as I don't see any Toast on the screen on boot.

As stated in comments, I was testing on a Redmi 1s, which is a Xiaomi phone, running MIUI.
I tested this same piece code on an emulator (Bluestacks to be precise) and it worked like a charm. This is probably why nobody had a solution! There's no problem in this code!
Turns out, as mentioned here, that the MIUI (my Android version is 4.3), needs another set of permission which is:
<action android:name="android.intent.action.REBOOT"/>
in the Manifest.
Secondly, MIUI seems to have set special permissions to auto-start the app - which can be set in here:
"Settings > Apps > YOUR_APP > Manage permissions"
There you need to enable "Autostart" option.
Hope it helps someone using Xiaomi's Redmi / Mi devices.
P.S. My test device was running MIUI-JHCMIBH45.0 when I encountered this issue.