MissingPluginException（在通道 dexterous.com/flutter/local_notifications 上找不到方法显示的实现）答案

【问题标题】：MissingPluginException(No implementation found for method show on channel dexterous.com/flutter/local_notifications)MissingPluginException（在通道 dexterous.com/flutter/local_notifications 上找不到方法显示的实现）
【发布时间】：2020-06-13 17:41:03
【问题描述】：

我已经尝试使用 Flutter 实现 Firebase 云消息传递，直到我使用“本地通知”插件来显示通知时我才成功

我的通知在前台工作正常，但在后台显示此错误：

[错误：flutter/lib/ui/ui_dart_state.cc(157)] 未处理的异常： MissingPluginException（找不到方法显示的实现频道 dexterous.com/flutter/local_notifications）

我使用 Firebase Cloud Messaging 6.0.9、本地通知 1.2.0+4 和最新的 Flutter

这是我的代码： NotificationHandler

import 'package:flutter_local_notifications/flutter_local_notifications.dart';

class NotificationHandler{
  static final flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin(); // make it a static field of the class

  static void initNotification()
  {

// initialise the plugin. app_icon needs to be a added as a drawable resource to the Android head project
    var initializationSettingsAndroid = AndroidInitializationSettings('@mipmap/ic_launcher');
    var initializationSettingsIOS = IOSInitializationSettings(
        onDidReceiveLocalNotification: onDidReceiveLocalNotification);
    var initializationSettings = InitializationSettings(
        initializationSettingsAndroid, initializationSettingsIOS);
    flutterLocalNotificationsPlugin.initialize(initializationSettings,
        onSelectNotification: onSelectNotification);
  }
  static Future onSelectNotification(String payload) async {
    if (payload != null) {
      print('notification payload: ' + payload);
    }

  }
  static Future onDidReceiveLocalNotification(int id, String title, String body, String payload) {
    print(title+" "+body);
  }

}

ShowNotification 方法

static void showNotification(data, data2) async {
      var androidPlatformChannelSpecifics = new AndroidNotificationDetails(
          'dexterous.com.flutter.local_notifications', 'your channel name', 'your channel description',
          importance: Importance.Max,
          priority: Priority.High);
      var iOSPlatformChannelSpecifics =
      new IOSNotificationDetails();
      var platformChannelSpecifics = new NotificationDetails(
          androidPlatformChannelSpecifics, iOSPlatformChannelSpecifics);

      await NotificationHandler.flutterLocalNotificationsPlugin
      .show(
        0,
        data,
        data2,
        platformChannelSpecifics,
        payload: 'Custom_Sound',
      );

  }

【问题讨论】：

按照以下步骤操作 1) 使用 flutter clean 命令 2) 卸载以前的应用程序 3) 重新安装应用程序
谢谢，问题已解决。这一步没用:(

标签： firebase flutter flutter-dependencies localnotification

【解决方案1】：

我找到了解决方案，为什么在平台方面我们不注册外部插件

像这样添加你的 FCMPluginRegistrant.java

public final  class FirebaseCloudMessagingPluginRegistrant {

    public static void registerWith(PluginRegistry registry) {

        if (alreadyRegisteredWith(registry)) {
            return;
        }
        FirebaseMessagingPlugin.registerWith(registry.registrarFor("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin"));
        FlutterLocalNotificationsPlugin.registerWith(registry.registrarFor("com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin"));


    }




    private static boolean alreadyRegisteredWith(PluginRegistry registry) {
        final String key = FirebaseCloudMessagingPluginRegistrant.class.getCanonicalName();
        if (registry.hasPlugin(key)) {
            return true;
        }
        registry.registrarFor(key);
        return false;
    }
}

然后在 Application.java 上调用它

  @Override
    public void registerWith(PluginRegistry registry) {



        FirebaseCloudMessagingPluginRegistrant.registerWith(registry);

    }

【讨论】：

这对我有用。尚未检查其他平台是否需要类似的解决方法。 import com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin
同时导入 io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin;在上面的第一段代码中。它对我有用。

【解决方案2】：

对于 Kotlin：应用程序.kt

package your.package.name

import io.flutter.app.FlutterApplication
import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback
import io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin
import io.flutter.view.FlutterMain
import io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService
import com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin

class Application : FlutterApplication(), PluginRegistrantCallback {

    override fun onCreate() {
        super.onCreate()
        FlutterFirebaseMessagingService.setPluginRegistrant(this);
        FlutterMain.startInitialization(this)
    }

    override fun registerWith(registry: PluginRegistry?) {
        if (!registry!!.hasPlugin("io.flutter.plugins.firebasemessaging")) {
            FirebaseMessagingPlugin.registerWith(registry!!.registrarFor("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin"));
        }
        if (!registry!!.hasPlugin("com.dexterous.flutterlocalnotifications")) {
                FlutterLocalNotificationsPlugin.registerWith(registry!!.registrarFor("com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin"));
        }
    }
}

【讨论】：

这似乎对我不起作用stackoverflow.com/questions/62820872/…

【解决方案3】：

当我在我的混合应用程序的本机部分中使用result.notImplemented 时，我遇到了同样的问题。当我将此方法替换为result.success(0)时，一切都解决了@

【讨论】：

【解决方案4】：

我只是先卸载应用程序，然后重新安装它，它解决了我的问题。

【讨论】：