使用StreamBuilder的TextField上的初始值

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  final Stream<String> _initialValueStream = Stream<String>.value("Initial Value");

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('StreamBuilder TextField Example'),
        ),
        body: Center(
          child: StreamBuilder<String>(
            stream: _initialValueStream,
            builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
              if (snapshot.hasData) {
                return TextField(
                  controller: TextEditingController(text: snapshot.data),
                );
              } else {
                return CircularProgressIndicator();
              }
            },
          ),
        ),
      ),
    );
  }
}