如何在Flutter中创建数字输入字段？

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('数字输入字段示例'),
        ),
        body: Center(
          child: NumberInputField(),
        ),
      ),
    );
  }
}

class NumberInputField extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(16.0),
      child: TextField(
        keyboardType: TextInputType.number,
        decoration: InputDecoration(
          labelText: '请输入数字',
          border: OutlineInputBorder(),
        ),
        onChanged: (value) {
          // 处理输入值的变化
          print(value);
        },
      ),
    );
  }
}