init

android/app/src/main/AndroidManifest.xml

@@ -29,12 +29,12 @@
                  while the Flutter UI initializes. After that, this theme continues
                  to determine the Window background behind the Flutter UI. -->
             <meta-data
-              android:name="io.flutter.embedding.android.NormalTheme"
-              android:resource="@style/NormalTheme"
-              />
+                android:name="io.flutter.embedding.android.NormalTheme"
+                android:resource="@style/NormalTheme"
+            />
             <intent-filter>
-                <action android:name="android.intent.action.MAIN"/>
-                <category android:name="android.intent.category.LAUNCHER"/>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
         <!-- Don't delete the meta-data below.
@@ -47,7 +47,7 @@
             android:name="id.flutter.flutter_background_service.BackgroundService"
             android:foregroundServiceType="dataSync"
         />
-        
+
         <receiver
             android:name=".widget.HomeWidget"
             android:exported="false"
@@ -67,7 +67,11 @@
                 android:resource="@xml/home_widget" />
         </receiver>
 
-        <service android:name=".KeepAliveService"/>
+        <service
+            android:name=".MyForegroundService"
+            android:enabled="true"
+            android:exported="false" />
+
     </application>
     <!-- Required to query activities that can process text, see:
          https://developer.android.com/training/package-visibility?hl=en and
@@ -76,8 +80,8 @@
          In particular, this is used by the Flutter engine in io.flutter.plugin.text.ProcessTextPlugin. -->
     <queries>
         <intent>
-            <action android:name="android.intent.action.PROCESS_TEXT"/>
-            <data android:mimeType="text/plain"/>
+            <action android:name="android.intent.action.PROCESS_TEXT" />
+            <data android:mimeType="text/plain" />
         </intent>
     </queries>
-</manifest>
+</manifest>

android/app/src/main/kotlin/tech/lolli/toolbox/ForegroundService.kt

@@ -0,0 +1,59 @@
+package tech.lolli.toolbox
+
+import android.app.*
+import android.content.Intent
+import android.os.Build
+import android.os.IBinder
+import androidx.core.app.NotificationCompat
+
+class MyForegroundService : Service() {
+
+    private val CHANNEL_ID = "ForegroundServiceChannel"
+
+    override fun onCreate() {
+        super.onCreate()
+        createNotificationChannel()
+    }
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        val notification = createNotification()
+        startForeground(1, notification)
+
+        // Exec your code here
+
+        return START_STICKY
+    }
+
+    override fun onBind(intent: Intent): IBinder? {
+        return null
+    }
+
+    private fun createNotificationChannel() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val serviceChannel = NotificationChannel(
+                CHANNEL_ID,
+                CHANNEL_ID,
+                NotificationManager.IMPORTANCE_DEFAULT
+            )
+            val manager = getSystemService(NotificationManager::class.java)
+            manager.createNotificationChannel(serviceChannel)
+        }
+    }
+
+    private fun createNotification(): Notification {
+        val notificationIntent = Intent(this, MainActivity::class.java)
+        val pendingIntent = PendingIntent.getActivity(
+            this,
+            0,
+            notificationIntent,
+            PendingIntent.FLAG_IMMUTABLE
+        )
+
+        return NotificationCompat.Builder(this, CHANNEL_ID)
+            .setContentTitle("App is running")
+            .setContentText("Click to open the app")
+            .setSmallIcon(R.drawable.ic_notification)
+            .setContentIntent(pendingIntent)
+            .build()
+    }
+}

android/app/src/main/kotlin/tech/lolli/toolbox/KeepAliveService.kt

@@ -1,18 +0,0 @@
-package tech.lolli.toolbox
-
-import android.app.Service
-import android.content.Intent
-
-import android.os.IBinder
-import org.jetbrains.annotations.Nullable
-
-class KeepAliveService : Service() {
-    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
-        return START_STICKY
-    }
-
-    @Nullable
-    override fun onBind(intent: Intent?): IBinder? {
-        return null
-    }
-}

android/app/src/main/kotlin/tech/lolli/toolbox/MainActivity.kt

@@ -18,8 +18,12 @@ class MainActivity: FlutterFragmentActivity() {
                         result.success(null)
                     }
                     "startService" -> {
-                        val intent = Intent(this@MainActivity, KeepAliveService::class.java)
-                        startService(intent)
+                        val serviceIntent = Intent(this, ForegroundService::class.java)
+                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                            startForegroundService(serviceIntent)
+                        } else {
+                            startService(serviceIntent)
+                        }
                     }
                     else -> {
                         result.notImplemented()