Flutter定时通知遇两类PlatformException：求错误分析与解决方案

错误一：应用启动时的invalid_icon异常 #

报错信息 #

E/flutter ( 7984): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: PlatformException(invalid_icon, The resource flutter_logo could not be found. Please make sure it has been added as a drawable resource to your Android head project., null, null)
E/flutter ( 7984): #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:651:7)
E/flutter ( 7984): #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:322:18)
E/flutter ( 7984): <asynchronous suspension>
E/flutter ( 7984): #2      AndroidFlutterLocalNotificationsPlugin.initialize (package:flutter_local_notifications/src/platform_flutter_local_notifications.dart:142:12)
E/flutter ( 7984): <asynchronous suspension>
E/flutter ( 7984): #3      NotificationService.initNotification (package:agriplus/Screens/Schedule%20Notification/notificationService.dart:23:5)
E/flutter ( 7984): <asynchronous suspension>

原因 #

初始化flutter_local_notifications时，Android端指定的图标flutter_logo不存在于项目的drawable资源目录中。

代码问题 #

在NotificationService的initNotification方法里，AndroidInitializationSettings传入了不存在的图标名称：

AndroidInitializationSettings initializationSettingsAndroid =
const AndroidInitializationSettings('flutter_logo');

解决方案 #

有两种处理方式：

• 添加图标资源：将名为flutter_logo的png图片放到Android项目的android/app/src/main/res/drawable目录下。
• 使用默认/现有图标：改为使用应用启动图标或系统默认图标：

// 使用应用启动图标（需确保mipmap目录有ic_launcher）
AndroidInitializationSettings initializationSettingsAndroid =
const AndroidInitializationSettings('@mipmap/ic_launcher');

// 或者使用系统默认图标
AndroidInitializationSettings initializationSettingsAndroid =
const AndroidInitializationSettings('');

错误二：点击定时按钮时的exact_alarms_not_permitted异常 #

报错信息 #

E/flutter ( 7984): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: PlatformException(exact_alarms_not_permitted, Exact alarms are not permitted, null, null)
E/flutter ( 7984): #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:651:7)
E/flutter ( 7984): #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:322:18)
E/flutter ( 7984): <asynchronous suspension>
E/flutter ( 7984): #2      AndroidFlutterLocalNotificationsPlugin.zonedSchedule (package:flutter_local_notifications/src/platform_flutter_local_notifications.dart:191:5)
E/flutter ( 7984): <asynchronous suspension>
E/flutter ( 7984): #3      FlutterLocalNotificationsPlugin.zonedSchedule (package:flutter_local_notifications/src/flutter_local_notifications_plugin.dart:352:7)
E/flutter ( 7984): <asynchronous suspension>

原因 #

Android 12（API 31）及以上版本，使用精确定时闹钟需要SCHEDULE_EXACT_ALARM权限，仅在AndroidManifest.xml中声明权限不够，还需要动态向用户申请权限，部分系统会限制该权限的自动授予。

代码问题 #

1. 仅在Manifest中声明了权限，但未实现动态权限申请逻辑。
2. 调用zonedSchedule时直接执行，未检查权限是否已授予。

解决方案 #

步骤1：添加权限处理依赖

在pubspec.yaml中添加permission_handler包：

dependencies:
  permission_handler: ^10.2.0

步骤2：在NotificationService中新增权限检查方法

import 'package:permission_handler/permission_handler.dart';

class NotificationService {
  // ... 原有代码 ...

  Future<bool> requestExactAlarmPermission() async {
    if (await Permission.scheduleExactAlarm.isGranted) {
      return true;
    } else {
      var status = await Permission.scheduleExactAlarm.request();
      return status.isGranted;
    }
  }

  // ... 原有代码 ...
}

步骤3：修改定时通知方法，先校验权限

Future scheduleNotification(
    {int id = 0,
      String? title,
      String? body,
      String? payLoad,
      required DateTime scheduledNotificationDateTime}) async {
  // 先检查权限
  bool hasPermission = await requestExactAlarmPermission();
  if (!hasPermission) {
    debugPrint("精确闹钟权限未授予，无法创建定时通知");
    // 可选：引导用户到设置页面开启权限
    // await openAppSettings();
    return;
  }

  return notificationsPlugin.zonedSchedule(
      id,
      title,
      body,
      tz.TZDateTime.from(
        scheduledNotificationDateTime,
        tz.local,
      ),
      await notificationDetails(),
      androidAllowWhileIdle: true,
      uiLocalNotificationDateInterpretation:
      UILocalNotificationDateInterpretation.absoluteTime);
}

额外优化建议 #

• 调整main函数初始化顺序，确保时区初始化完成后再初始化通知：

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  tz.initializeTimeZones(); // 先初始化时区
  await NotificationService().initNotification(); // 等待通知初始化完成
  // ... 其他代码 ...
}

• iOS平台需在Info.plist中添加权限描述：

<key>NSAlertUsageDescription</key>
<string>需要发送通知提醒您</string>
<key>NSBadgeUsageDescription</key>
<string>需要更新应用角标</string>
<key>NSSoundUsageDescription</key>
<string>需要播放通知声音</string>

内容的提问来源于stack exchange，提问作者Ahmed Raza