This time I needed to add android:process to my manifest, in order to have a separate never-ending process, and to update UI.
I have started an empty project, then I have added Service: File -> New -> Service - Service, then I have added Broadcast: File -> New -> Other -> Broadcast receiver.
In AndroidManifest.xml I have added FOREGROUND_SERVICE permission and android:process. Now my manifest looks like:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.milosev.sendbroadcastfromanotherprocess">
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<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.SendBroadcastFromAnotherProcess">
<receiver
android:name=".MyReceiver"
android:enabled="true"
android:exported="true" />
<service
android:name=".MyService"
android:enabled="true"
android:exported="true"
android:process=":MyService" />
<activity
android:name=".MainActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
In gradle I have added coroutines:
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.1"
My gradle looks like:
plugins {
id 'com.android.application'
id 'org.jetbrains.kotlin.android'
}
android {
compileSdk 32
defaultConfig {
applicationId "com.milosev.sendbroadcastfromanotherprocess"
minSdk 21
targetSdk 32
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
jvmTarget = '1.8'
}
}
dependencies {
implementation 'androidx.core:core-ktx:1.7.0'
implementation 'androidx.appcompat:appcompat:1.4.1'
implementation 'com.google.android.material:material:1.5.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.3'
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.1"
}
MyService.kt:
*2023-04-04 UPDATE: * To debug MyService you will have to attach to this process with debugger.
package com.milosev.sendbroadcastfromanotherprocess
import android.app.Notification
import android.app.NotificationChannel
import android.app.NotificationManager
import android.app.Service
import android.content.Context
import android.content.Intent
import android.graphics.Color
import android.os.Build
import android.os.IBinder
import androidx.annotation.RequiresApi
import androidx.core.app.NotificationCompat
import kotlinx.coroutines.*
class MyService : Service(), CoroutineScope by MainScope() {
private var job: Job? = null
override fun onBind(intent: Intent): IBinder {
TODO("Return the communication channel to the service.")
}
@RequiresApi(Build.VERSION_CODES.O)
override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
when (intent?.action) {
"startForeground" -> {
val channelId = createNotificationChannel("my_service", "My Background Service")
val notificationBuilder = NotificationCompat.Builder(this, channelId)
val notification = notificationBuilder.setOngoing(true)
.setContentTitle("test")
.setContentText("test")
.setSmallIcon(R.mipmap.ic_launcher)
.setPriority(1)
.setCategory(Notification.CATEGORY_SERVICE)
.build()
startForeground(101, notification)
val context = this
job = launch {
while(true) {
val myIntent = Intent(context, MyReceiver::class.java).setAction("MyAction")
myIntent.putExtra("message", "test")
sendBroadcast(myIntent);
delay(1_000)
}
}
}
}
if (intent?.action.equals("stopForeground")) {
job?.cancel()
stopForeground(true)
stopSelfResult(startId)
}
return START_STICKY;
}
@RequiresApi(Build.VERSION_CODES.O)
private fun createNotificationChannel(channelId: String, channelName: String): String {
val chan = NotificationChannel(
channelId,
channelName, NotificationManager.IMPORTANCE_NONE
)
chan.lightColor = Color.RED
chan.lockscreenVisibility = Notification.VISIBILITY_PRIVATE
val service = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
service.createNotificationChannel(chan)
return channelId
}
}
MyReceiver.kt:
package com.milosev.sendbroadcastfromanotherprocess
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import androidx.localbroadcastmanager.content.LocalBroadcastManager
class MyReceiver : BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
val myIntent = Intent(context, MainActivity::class.java).setAction("MyAction")
myIntent.putExtra("message", "test")
LocalBroadcastManager.getInstance(context).sendBroadcast(myIntent)
}
}
MainActivity.kt:
package com.milosev.sendbroadcastfromanotherprocess
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.content.IntentFilter
import android.os.Build
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.widget.TextView
import androidx.annotation.RequiresApi
import androidx.localbroadcastmanager.content.LocalBroadcastManager
class MainActivity : AppCompatActivity() {
val myReceiver: BroadcastReceiver = MyReceiver()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val filter = IntentFilter("MyAction")
registerReceiver(myReceiver, filter)
var textView = findViewById(R.id.myText) as TextView
val broadCastReceiver = object : BroadcastReceiver() {
override fun onReceive(contxt: Context?, intent: Intent?) {
when (intent?.action) {
"MyAction" -> {
textView = findViewById(R.id.myText) as TextView
textView.text = intent.getStringExtra("message")
}
}
}
}
LocalBroadcastManager.getInstance(this)
.registerReceiver(broadCastReceiver, IntentFilter("MyAction"))
}
@RequiresApi(Build.VERSION_CODES.O)
fun onClick(view: View) {
val intent = Intent(this, MyService::class.java)
intent.action = "startForeground"
startForegroundService(intent)
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="@+id/myText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="onClick"
android:text="Button"
tools:layout_editor_absoluteX="106dp"
tools:layout_editor_absoluteY="110dp" />
</androidx.constraintlayout.widget.ConstraintLayout>
Example download from
here.