问颤栗:简单的通知不起作用？

EN

import 'dart:ui';    
import 'package:flutter/material.dart';
import 'package:push_notification/api/notification_api.dart';
import 'package:push_notification/util/SizeConfig.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Notification',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {

  @override
  Widget build(BuildContext context) {
    SizeConfig().init(context);
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      backgroundColor: Colors.white,
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.start,
          children:  <Widget>[
            Icon(
              Icons.android,
              size: 80.0,
              color: Colors.lightGreen,
            ),
            SizedBox(height: 20,),
            Text(
              'Notification',
              style: const TextStyle(fontWeight: FontWeight.bold,fontSize: 50,color: Colors.black26),
            ),
            SizedBox(height: 20,),
  /*          buildButton(
              title:"Simple Notification",
              icon:Icons.notifications,
              onClicked:()=>NotificationApi.notificationDetails,
            ),*/
            RaisedButton(
              child: Text('Simple Notification'),
              onPressed: () => NotificationApi.showNotification(title: "john",body: "just eat some snacks"),
            ),
            SizedBox(height: 20,),
            buildButton(
                title:"Schedule Notification",
                icon:Icons.notifications,
                onClicked:(){}
            ),
            SizedBox(height: 20,),
            buildButton(
                title:"Remove Notification",
                icon:Icons.notifications,
                onClicked:(){}
            ),
          ],
        ),
      ),
     // This trailing comma makes auto-formatting nicer for build methods.
    );
  }

  Widget buildButton({required String title, required IconData icon, required  Function()
  onClicked}) {
     return RaisedButton(
       onPressed: () {onClicked;},
       color: Color.fromRGBO(0, 0, 0, 10.0),
       child: Padding(
         padding: EdgeInsets.fromLTRB(
             SizeConfig.blockSizeHorizontal * 5,
             0,
             SizeConfig.blockSizeHorizontal * 5,
             0),
         child: Row(
           mainAxisAlignment: MainAxisAlignment.spaceBetween,
           children: <Widget>[
             Text(
               title,
               style: TextStyle(
                 fontSize: 20,
                 fontWeight: FontWeight.w700,
                 color: Colors.white,
               ),
             ),
             Icon(
               icon,
               color: Colors.white,
             )
           ],
         ),
       ),
     );
  }
}

import 'package:flutter_local_notifications/flutter_local_notifications.dart';

class NotificationApi {
  static final _notification = FlutterLocalNotificationsPlugin();

  static Future notificationDetails() async{
    return const NotificationDetails(
      android: AndroidNotificationDetails(
        'channel id',
        'channel name',
        channelDescription: 'channel description',
        importance: Importance.max
      ),
      iOS: IOSNotificationDetails(),
    );
  }

  static Future showNotification({
  int id = 0,
  String? title,
  String? body,
  String? payload,
})
  async => _notification.show(id, title, body, await notificationDetails(),payload:payload);

}

 V/AutofillManager(17133): requestHideFillUi(null): anchor = null
    D/CompatibilityChangeReporter(17133): Compat change id reported: 160794467; UID 10002; state: ENABLED
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133): Failed to handle method call
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133): 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(17133):   at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.setSmallIcon(FlutterLocalNotificationsPlugin.java:312)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.createNotification(FlutterLocalNotificationsPlugin.java:219)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.showNotification(FlutterLocalNotificationsPlugin.java:1017)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.show(FlutterLocalNotificationsPlugin.java:1358)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.onMethodCall(FlutterLocalNotificationsPlugin.java:1234)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:262)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at io.flutter.embedding.engine.dart.DartMessenger.invokeHandler(DartMessenger.java:296)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at io.flutter.embedding.engine.dart.DartMessenger.lambda$dispatchMessageToQueue$0$DartMessenger(DartMessenger.java:320)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at io.flutter.embedding.engine.dart.-$$Lambda$DartMessenger$TsixYUB5E6FpKhMtCSQVHKE89gQ.run(Unknown Source:12)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at android.os.Handler.handleCallback(Handler.java:938)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at android.os.Handler.dispatchMessage(Handler.java:99)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at android.os.Looper.loopOnce(Looper.java:233)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at android.os.Looper.loop(Looper.java:344)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at android.app.ActivityThread.main(ActivityThread.java:8223)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at java.lang.reflect.Method.invoke(Native Method)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:589)
    E/MethodChannel#dexterous.com/flutter/local_notifications(17133):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1071)
    E/flutter (17133): [ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: PlatformException(error, Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference, null, java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference
    E/flutter (17133):  at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.setSmallIcon(FlutterLocalNotificationsPlugin.java:312)
    E/flutter (17133):  at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.createNotification(FlutterLocalNotificationsPlugin.java:219)
    E/flutter (17133):  at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.showNotification(FlutterLocalNotificationsPlugin.java:1017)
    E/flutter (17133):  at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.show(FlutterLocalNotificationsPlugin.java:1358)
    E/flutter (17133):  at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.onMethodCall(FlutterLocalNotificationsPlugin.java:1234)
    E/flutter (17133):  at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:262)
    E/flutter (17133):  at io.flutter.embedding.engine.dart.DartMessenger.invokeHandler(DartMessenger.java:296)
    E/flutter (17133):  at io.flutter.embedding.engine.dart.DartMessenger.lambda$dispatchMessageToQueue$0$DartMessenger(DartMessenger.java:320)
    E/flutter (17133):  at io.flutter.embedding.engine.dart.-$$Lambda$DartMessenger$TsixYUB5E6FpKhMtCSQVHKE89gQ.run(Unknown Source:12)
    E/flutter (17133):  at android.os.Handler.handleCallback(Handler.java:938)
    E/flutter (17133):  at android.os.Handler.dispatchMessage(Handler.java:99)
    E/flutter (17133):  at android.os.Looper.loopOnce(Looper.java:233)
    E/flutter (17133):  at android.os.Looper.loop(Looper.java:344)
    E/flutter (17133):  at android.app.ActivityThread.main(ActivityThread.java:8223)
    E/flutter (17133):  at java.lang.reflect.Method.invoke(Native Method)
    E/flutter (17133):  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:589)
    E/flutter (17133):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1071)
    E/flutter (17133): )
    E/flutter (17133): #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:607:7)
    E/flutter (17133): #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:177:18)
    E/flutter (17133): <asynchronous suspension>
    E/flutter (17133): #2      FlutterLocalNotificationsPlugin.show (package:flutter_local_notifications/src/flutter_local_notifications_plugin.dart:215:7)
    E/flutter (17133): <asynchronous suspension>
    E/flutter (17133): 
    E/BLASTBufferQueue(17133): [SurfaceView[com.example.push_notification/com.example.push_notification.MainActivity]#1](f:0,a:2) isEGL=1, mPendingRelease.size()=1, mMaxAcquiredBuffers=4, currentMaxAcquiredBufferCount=2
    E/BLASTBufferQueue(17133): [SurfaceView[com.example.push_notification/com.example.push_notification.MainActivity]#1](f:0,a:3) isEGL=1, mPendingRelease.size()=2, mMaxAcquiredBuffers=4, currentMaxAcquiredBufferCount=2