从另一个有状态小部件类获取文本字段数据

import 'package:flutter/material.dart';

class TextFieldWidget extends StatefulWidget {
  @override
  _TextFieldWidgetState createState() => _TextFieldWidgetState();
}

class _TextFieldWidgetState extends State<TextFieldWidget> {
  String textFieldValue = '';

  @override
  Widget build(BuildContext context) {
    return TextField(
      onChanged: (value) {
        setState(() {
          textFieldValue = value;
        });
      },
    );
  }
}

class AnotherWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        TextFieldWidget(),
        RaisedButton(
          onPressed: () {
            // 获取文本字段数据
            _handleTextFieldData(context);
          },
          child: Text('获取文本字段数据'),
        ),
      ],
    );
  }

  void _handleTextFieldData(BuildContext context) {
    final textFieldWidget = context.findAncestorWidgetOfExactType<TextFieldWidget>();
    if (textFieldWidget != null) {
      final textFieldData = textFieldWidget.textFieldValue;
      // 处理文本字段数据
      print('获取到的文本字段数据：$textFieldData');
    }
  }
}