BottomaNavigationBarのonTapの引数にint以外の値を渡したい

Question

onItemTapの引数にintに加えて関数を渡したいのですが、onTapがintしか受付ないので、どうすれば渡すことができますか？

import 'package:flutter/material.dart';

enum TabItem { talent, message, setting }

class NavigationBar extends StatelessWidget {
  // final TabItem currentTab;
  final void Function(int) onItemTap;
  // final TabItem tabItem;
  const NavigationBar({Key key, this.onItemTap}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return BottomNavigationBar(items: <BottomNavigationBarItem>[
      BottomNavigationBarItem(icon: Image.asset("assets/talent.png"), title: Text('タレント')),
      BottomNavigationBarItem(icon: Image.asset("assets/message.png"), title: Text('リクエスト')),
      BottomNavigationBarItem(icon: Image.asset("assets/setting.png"), title: Text('設定')),
    ], 
    fixedColor: Colors.blueAccent,
    type: BottomNavigationBarType.fixed,
    onTap: onItemTap
    );
  }
}

Answer 1

こんな感じでしょうか？

class NavigationBar extends StatelessWidget {
  // final TabItem currentTab;
  final void Function(int, Function) onItemTap;
  // final TabItem tabItem;
  const NavigationBar({Key key, this.onItemTap}) : super(key: key);
  
  void _onItemTap(int val) {
    this.onItemTap(val, ((){print("Clicked");}));
  }

  @override
  Widget build(BuildContext context) {
    return BottomNavigationBar(items: <BottomNavigationBarItem>[
      BottomNavigationBarItem(icon: Image.asset("assets/talent.png"), title: Text('タレント')),
      BottomNavigationBarItem(icon: Image.asset("assets/message.png"), title: Text('リクエスト')),
      BottomNavigationBarItem(icon: Image.asset("assets/setting.png"), title: Text('設定')),
    ], 
    fixedColor: Colors.blueAccent,
    type: BottomNavigationBarType.fixed,
    onTap: _onItemTap
    );
  }
}

NavigationBar(
  onItemTap: (int val, Function func) {
    print(val);
    func.call();
  }              
)