При попытке показать уведомления от flutter_local_notification выдает следующую ошибку:
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): Failed to handle method call
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.setSmallIcon(FlutterLocalNotificationsPlugin.java:188)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.createNotification(FlutterLocalNotificationsPlugin.java:146)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.showNotification(FlutterLocalNotificationsPlugin.java:688)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.show(FlutterLocalNotificationsPlugin.java:827)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.onMethodCall(FlutterLocalNotificationsPlugin.java:750)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:226)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at io.flutter.embedding.engine.dart.DartMessenger.handleMessageFromDart(DartMessenger.java:85)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at io.flutter.embedding.engine.FlutterJNI.handlePlatformMessage(FlutterJNI.java:631)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at android.os.MessageQueue.nativePollOnce(Native Method)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at android.os.MessageQueue.next(MessageQueue.java:325)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at android.os.Looper.loop(Looper.java:142)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at android.app.ActivityThread.main(ActivityThread.java:6494)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at java.lang.reflect.Method.invoke(Native Method)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
E/MethodChannel#dexterous.com/flutter/local_notifications(10962): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
E/flutter (10962): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: PlatformException(error, Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference, null)
E/flutter (10962): #0 StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:569:7)
E/flutter (10962): #1 MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:156:18)
E/flutter (10962): <asynchronous suspension>
E/flutter (10962): #2 MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:329:12)
E/flutter (10962): #3 AndroidFlutterLocalNotificationsPlugin.show (package:flutter_local_notifications/src/platform_flutter_local_notifications.dart:137:21)
E/flutter (10962): #4 FlutterLocalNotificationsPlugin.show (package:flutter_local_notifications/src/flutter_local_notifications_plugin.dart:136:13)
E/flutter (10962): #5 NotificationPlugin.showNotification (package:pig_salang/models/notification_plugin.dart:94:43)
E/flutter (10962): #6 WelcomeScreen.build.<anonymous closure> (package:pig_salang/screens/welcome_screen.dart:42:36)
E/flutter (10962): #7 WelcomeScreen.build.<anonymous closure> (package:pig_salang/screens/welcome_screen.dart:41:26)
E/flutter (10962): #8 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:779:19)
E/flutter (10962): #9 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:862:36)
E/flutter (10962): #10 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:182:24)
E/flutter (10962): #11 TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:504:11)
E/flutter (10962): #12 BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:282:5)
E/flutter (10962): #13 BaseTapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:217:7)
E/flutter (10962): #14 PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:475:9)
E/flutter (10962): #15 PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:76:12)
E/flutter (10962): #16 PointerRouter._dispatchEventToRoutes.<anonymous closure> (package:flutter/src/gestures/pointer_router.dart:122:9)
E/flutter (10962): #17 _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:379:8)
E/flutter (10962): #18 PointerRouter._dispatchEventToRoutes (package:flutter/src/gestures/pointer_router.dart:120:18)
E/flutter (10962): #19 PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:106:7)
E/flutter (10962): #20 GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:218:19)
E/flutter (10962): #21 GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:198:22)
E/flutter (10962): #22 GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:156:7)
E/flutter (10962): #23 GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:102:7)
E/flutter (10962): #24 GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:86:7)
E/flutter (10962): #25 _rootRunUnary (dart:async/zone.dart:1196:13)
E/flutter (10962): #26 _CustomZone.runUnary (dart:async/zone.dart:1085:19)
E/flutter (10962): #27 _CustomZone.runUnaryGuarded (dart:async/zone.dart:987:7)
E/flutter (10962): #28 _invoke1 (dart:ui/hooks.dart:275:10)
E/flutter (10962): #29 _dispatchPointerDataPacket (dart:ui/hooks.dart:184:5)
E/flutter (10962):
Насколько я понял, подобные ошибки были показаны из-за значка. Я добавил, что использовал все возможные способы добавления значков, но он не выдает ошибку постоянно. Очевидно, я перезапускаю приложение после каждого изменения, чтобы убедиться, что я не получаю сообщение об ошибке.
Мой код выглядит так:
initializePlatformSpecifics() {
var initializeAndroidSettings = AndroidInitializationSettings('app_icon'); <--- Here
var initializeIOSSettings = IOSInitializationSettings(
requestAlertPermission: false,
requestBadgePermission: true,
requestSoundPermission: true,
onDidReceiveLocalNotification: (id, title, body, payload) async {
ReceivedNotification receivedNotification = ReceivedNotification(
id: id, title: title, body: body, payload: payload);
didReceivedLocalNotificationSubject.add(receivedNotification);
},
);
initializeSettings = InitializationSettings(
initializeAndroidSettings, initializeIOSSettings);
}
Я следил за руководством. Дело в том, что когда я пытаюсь показать уведомление, появляется указанная выше трассировка. 
Я сделал значки уведомлений в Android Studio - ›app -› main - ›res -› Image Asssets - ›Значок уведомлений, затем я сделал значок с именем app_icon, который я использовал для инициализации уведомления.
Поскольку это не сработало, я также попробовал:
var initializeAndroidSettings = AndroidInitializationSettings('@mipmap/ic_launcher');
Это тоже не сработало. Любая помощь будет оценена по достоинству !!!
