Flutter:如何移动TextField字符计数器？

TextEditingController _textController = TextEditingController();

TextField(
  controller: _textController,
  ...
)

int _characterCount = 0;

@override
void initState() {
  super.initState();
  _textController.addListener(_updateCharacterCount);
}

void _updateCharacterCount() {
  setState(() {
    _characterCount = _textController.text.length;
  });
}

Text('Character count: $_characterCount'),

import 'package:flutter/material.dart';

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

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

class TextFieldCharacterCounter extends StatefulWidget {
  @override
  _TextFieldCharacterCounterState createState() =>
      _TextFieldCharacterCounterState();
}

class _TextFieldCharacterCounterState extends State<TextFieldCharacterCounter> {
  TextEditingController _textController = TextEditingController();
  int _characterCount = 0;

  @override
  void initState() {
    super.initState();
    _textController.addListener(_updateCharacterCount);
  }

  void _updateCharacterCount() {
    setState(() {
      _characterCount = _textController.text.length;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('TextField Character Counter'),
      ),
      body: Column(
        children: [
          TextField(
            controller: _textController,
            decoration: InputDecoration(
              labelText: 'Enter some text',
            ),
          ),
          SizedBox(height: 10),
          Text('Character count: $_characterCount'),
        ],
      ),
    );
  }
}