iOS 出现 Flutter Workmanager 插件实现缺失错误

Question

我正在尝试使用 workmanager: ^0.2.0 插件作为 flutter 项目中的后台进程。虽然运行 iOS 中的应用程序会抛出如下错误，但在 Android 中插件可以无缝运行

MissingPluginException(No implementation found for method initialize on channel be.tramckrijte.workmanager/foreground_channel_work_manager)
#0      MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:319:7)
<asynchronous suspension>
#1      Workmanager.initialize (package:workmanager/src/workmanager.dart:100:30)
#2      main (package:worksample/main.dart:29:15)

我在 AppDelegate.swift 代码中手动注册了 Workmanager 插件，它仍然没有在 GeneratedPluginRegistrant.m class 文件中自动生成插件注册代码。

下面是我的代码片段，

import UIKit
import Flutter
import workmanager

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    GeneratedPluginRegistrant.register(with: self)
    UIApplication.shared.setMinimumBackgroundFetchInterval(TimeInterval(60*15))
    UNUserNotificationCenter.current().delegate = self
    
    WorkmanagerPlugin.setPluginRegistrantCallback { registry in
        AppDelegate.registerPlugins(with: registry)
    }
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
    
    static func registerPlugins(with registry: FlutterPluginRegistry) {
               GeneratedPluginRegistrant.register(with: registry)
          }
       
    override func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
         completionHandler(.alert) 
     }
    
}

下面生成的文件中缺少 WorkManager 插件

//
//  Generated file. Do not edit.
//

#import "GeneratedPluginRegistrant.h"

#if __has_include(<flutter_native_timezone/FlutterNativeTimezonePlugin.h>)
#import <flutter_native_timezone/FlutterNativeTimezonePlugin.h>
#else
@import flutter_native_timezone;
#endif

#if __has_include(<shared_preferences/FLTSharedPreferencesPlugin.h>)
#import <shared_preferences/FLTSharedPreferencesPlugin.h>
#else
@import shared_preferences;
#endif

@implementation GeneratedPluginRegistrant

+ (void)registerWithRegistry:(NSObject<FlutterPluginRegistry>*)registry {
  [FlutterNativeTimezonePlugin registerWithRegistrar:[registry registrarForPlugin:@"FlutterNativeTimezonePlugin"]];
  [FLTSharedPreferencesPlugin registerWithRegistrar:[registry registrarForPlugin:@"FLTSharedPreferencesPlugin"]];
}

@end

我该如何解决这个问题？

Answer 1

通过在 AppDelegate.swift class 中添加以下更改解决了该问题。

import UIKit
import Flutter
import workmanager
import shared_preferences

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
 
    
    GeneratedPluginRegistrant.register(with: self)
    
    WorkmanagerPlugin.register(with: self.registrar(forPlugin: "be.tramckrijte.workmanager.WorkmanagerPlugin"))
    
    UNUserNotificationCenter.current().delegate = self

    UIApplication.shared.setMinimumBackgroundFetchInterval(TimeInterval(60*15))

    
    WorkmanagerPlugin.setPluginRegistrantCallback { registry in
        AppDelegate.registerPlugins(with: registry)
         FLTSharedPreferencesPlugin.register(with: registry.registrar(forPlugin: "io.flutter.plugins.sharedpreferences.SharedPreferencesPlugin"))
        
       
           
    }
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
    
    static func registerPlugins(with registry: FlutterPluginRegistry) {
               GeneratedPluginRegistrant.register(with: registry)
          }
       
    override func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
         completionHandler(.alert) 
     }
    
}

iOS 出现 Flutter Workmanager 插件实现缺失错误

Flutter Workmanager plugin implementation missing error occurs in iOS

ios

flutter

flutter-plugin