PrivacySettingsViewController.swift

import Flutter
import UIKit

class PrivacySettingViewController: UIViewController {
    
    static let channelName: String = "your.app.identifier/privacy" // これはグローバルで他とかぶらない名前をつけます
    
    // other functions ...
  
    
    private func createFlutterChannel(_ flutterViewController: FlutterViewController) {
        let privacyChannel = FlutterMethodChannel(name: channelName, binaryMessenger: flutterViewController.binaryMessenger)
        privacyChannel.setMethodCallHandler({ (call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
            guard call.method == "setPrivacyFlag" || call.method == "getPrivacyFlag" else {
                result(FlutterMethodNotImplemented)
                return
            }
            let privacyHandler = PrivacyHandler()
            if call.method == "setPrivacyFlag" {
                guard let isOn: Bool = (call.arguments as? [Any])?.first as? Bool else {
                    result(FlutterMethodNotImplemented)
                    return
                }
                privacyHandler.privacyFlag = isOn
                result(isOn)
            }
        
            if call.method == "getPrivacyFlag" {
                let isOn: Bool = privacyHandler.privacyFlag
                result(isOn)
            }
        })
    }
}