Flutter TextField正则表达式清除文本输入

import 'package:flutter/material.dart';
import 'dart:core';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  TextEditingController _controller = TextEditingController();

  void clearText() {
    setState(() {
      // 使用正则表达式清除非数字字符
      _controller.text = _controller.text.replaceAll(RegExp(r'[^0-9]'), '');
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('TextField正则表达式清除文本输入'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            TextField(
              controller: _controller,
            ),
            RaisedButton(
              child: Text('清除文本'),
              onPressed: clearText,
            ),
          ],
        ),
      ),
    );
  }
}