TextFormField验证器参数

Question

我正在尝试制作一个自定义小部件TextFormField，但是验证器:验证器会显示一个错误。

参数类型dynamic Function()不能分配给参数类型'String? Function(String?)?'.dartargument_type_not_assignable dynamic Function()验证程序包:store/widgets/mytextformfield.dart. type

mytextformfield.dart <<<文件小部件TextFormField

import 'package:flutter/material.dart';



class MyTextFormField extends StatelessWidget {
  final Function() validator;
  final bool obserText;
  final String name;

  const MyTextFormField({
    Key? key,
    required this.obserText,
    required this.validator,
    required this.name,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return TextFormField(
      obscureText: obserText,
      **validator: validator,**
      decoration: InputDecoration(
        border: const OutlineInputBorder(),
        hintText: name,
      ),
    );
  }
}

login.dart

MyTextFormField(
      obserText: obserText,
      name: "Email",
          validator: (value) {
          if (value == "") {
         return "Please Fill Email";
        } else if (!regExp.hasMatch(value!)) {
          return "Email is Invaild";
        }
      return "";
      },
     )

Answer 1

替换这一行：

final Function() validator;

至：

final FormFieldValidator<String>? validator;

Answer 2

尝试只定义为Function而不是Function()

final Function validator;

Answer 3

更改：

final Function() validator;

通过以下方式：

final FormFieldValidator<String>? validator

正如在TextFormField类中声明的那样