flutter - 如何将颤动文本编辑控制器值从一个无状态小部件传递到另一个无状态小部件

Question

这是 main.dart 文件：

import 'package:flutter/material.dart';
import 'package:untitled/button.dart';
import 'package:untitled/form.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[MyForm(), MyButton()],
        ),
      ),
    );
  }
}

这是 form.dart 文件：

import 'package:flutter/material.dart';

class MyForm extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    TextEditingController x = TextEditingController();
    return Container(
      child: Center(
        child: TextField(
          controller: x,
          decoration: InputDecoration(labelText: "Name"),
        ),
      ),
    );
  }
}

这是 button.dart 文件：

import 'package:flutter/material.dart';

class MyButton extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      child: Center(
        child: ElevatedButton(
          onPressed: () {
            //if I press this button the textediting field will show 10
          },
          child: Text("Pass 10"),
        ),
      ),
    );
  }
}

1. 如果我按下 button.dart 中的按钮，如何在文本编辑字段中显示数据？
   
2. 做这些事情的最佳方法是什么？
   
3. 我应该在 statelesswidget 中使用 statefulwidgets 还是在 statefulwidgets 中使用 statelesswidgets？

我的想法是使用redux或provider来传递这种东西。虽然我不知道这个简单的东西是否需要状态管理系统。

Answer 1

您需要提升状态（在主中创建您的控制器并将其传递给孩子）

// main.dart
class _MyHomePageState extends State<MyHomePage> {
  TextEditingController x = TextEditingController();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[MyForm(x), MyButton(x)],
        ),
      ),
    );
  }
}

class MyForm extends StatelessWidget {
  MyForm(this.x);
  final TextEditingController x;
  @override
  Widget build(BuildContext context) {
    return Container(
      child: Center(
        child: TextField(
          controller: x,
          decoration: InputDecoration(labelText: "Name"),
        ),
      ),
    );
  }
}

class MyButton extends StatelessWidget {
  MyButton(this.x);
  final TextEditingController x;
  @override
  Widget build(BuildContext context) {
    return Container(
      child: Center(
        child: ElevatedButton(
          onPressed: () {
            x...
            //if I press this button the textediting field will show 10
          },
          child: Text("Pass 10"),
        ),
      ),
    );
  }
}