flutter - Flutter：如何使用钩子来改变 textformfield 中文本的可见性？

Question

我正在尝试将我的TextFormField逻辑转移到钩子上，但我正在尝试的是似乎不起作用。

我的自定义钩子，

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';

enum Index { email, password }

TextFormField useTextFormField(Index index) {
  return use(_CustomHook(index: index));
}

class _CustomHook extends Hook<TextFormField> {
  final Index index;
  _CustomHook({@required this.index});

  @override
  _CustomHookState createState() => _CustomHookState();
}

class _CustomHookState extends HookState<TextFormField, _CustomHook> {
  Index index;

  @override
  TextFormField build(BuildContext context) {
    final visible = useState(false);
   // useEffect((){
    //  print('in');
   //visible.value=!visible.value;
     // print(visible.value.toString());
     // return;
   // },const []);
    return TextFormField(
      decoration: InputDecoration(
          hintText: 'some help',
          suffixIcon: IconButton(
            onPressed: () { 
              visible.value = !visible.value;}, //<--- here
            icon: Icon(visible.value ? Icons.visibility : Icons.visibility_off),
          )),
      validator: (text) {
        if (text.isEmpty) return 'enter something';

        return null;
      },
      obscureText: index == Index.email ? visible.value : true,
    );
  }
}

我是钩子的新手，我不知道我可以使用useState()并且useEffect()，如果有人可以提供帮助