How do I schedule a notification in Flutter?

Question

Im using the flutter_local_notifications package and im trying to schedule a notification in my Android device.

I successfully created a notification using this package but neither of the scheduled ones seems to work for me

My AndroidManifest.xml looks like this:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="...">
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
<uses-permission android:name="android.permission.VIBRATE" />

<receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationReceiver" />
<receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver">
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED"></action>
    </intent-filter>
</receiver>
<application
    android:name="io.flutter.app.FlutterApplication"
    android:label="notificaciones"
    android:icon="@mipmap/ic_launcher">
    <activity
        android:name=".MainActivity"
        android:launchMode="singleTop"
        android:theme="@style/LaunchTheme"
        android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density"
        android:hardwareAccelerated="true"
        android:windowSoftInputMode="adjustResize">
        <meta-data
            android:name="io.flutter.app.android.SplashScreenUntilFirstFrame"
            android:value="true" />
        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>
</application>

I added android.enableAapt2=false to the gradle.properties due to

AAPT: error: unknown element <receiver> found as mentioned in this thread to avoid a build error.

My code looks like this:

import 'package:flutter/material.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: new MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin;

  Future onSelectNotification(String payload) {
    showDialog(
        context: context,
        builder: (_) => AlertDialog(
              title: Text("ALERT"),
              content: Text("CONTENT: $payload"),
            ));
  }

  showNotification() async {
    var android = AndroidNotificationDetails(
        'channel id', 'channel name', 'channel description');
    var iOS = IOSNotificationDetails();
    var platform = NotificationDetails(android, iOS);
    var scheduledNotificationDateTime =
        new DateTime.now().add(Duration(seconds: 10));
    await flutterLocalNotificationsPlugin.schedule(0, 'Title ', 'Body', scheduledNotificationDateTime, platform);
  }

  @override
  void initState() {
    super.initState();
    flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();
    var android = AndroidInitializationSettings('@mipmap/ic_launcher');
    var iOS = IOSInitializationSettings();
    var initSettings = InitializationSettings(android, iOS);
    flutterLocalNotificationsPlugin.initialize(initSettings,
        selectNotification: onSelectNotification);
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text("Demo"),
      ),
      body: new Center(
        child: new Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[],
        ),
      ),
      floatingActionButton: new FloatingActionButton(
        onPressed: showNotification,
        child: new Icon(Icons.notifications),
      ),
    );
  }
}

Answer 1

Thanks to @pskink , I realized that I am supposed to put the receiver of the AndroidManifest.xml inside the application tag.

So the final AndroidManifest.xml stands like this:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="...">
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
<uses-permission android:name="android.permission.VIBRATE" />
<application
    android:name="io.flutter.app.FlutterApplication"
    android:label="notificaciones"
    android:icon="@mipmap/ic_launcher">
    <receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationReceiver" />
    <receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver">
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED"></action>
        </intent-filter>
    </receiver>
    <activity
        android:name=".MainActivity"
        android:launchMode="singleTop"
        android:theme="@style/LaunchTheme"
        android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density"
        android:hardwareAccelerated="true"
        android:windowSoftInputMode="adjustResize">
        <meta-data
            android:name="io.flutter.app.android.SplashScreenUntilFirstFrame"
            android:value="true" />
        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>
</application>

and theandroid.enableAapt2=false in the gradle.properties is not needed anymore. The rest of the code stays as it is.