flutter - 来自另一个类的文本编辑控制器

Question

我对 flutter 还很陌生，有人可以帮助我吗？请

我希望一旦单击 RawMaterialButton()，我在 TextField() 中编写的内容就会在 container() 类中显示为文本。

void main() => runApp(mainApp());

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

class chat extends StatefulWidget {
  const chat({Key? key}) : super(key: key);

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

class _chatState extends State<chat> {
  bool changeClass = false;
  changeClassValue() {
    setState(() {
      changeClass = !changeClass;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: changeClass
          ? container(
              text: _textFieldState().textController.text,
            )
          : textField(
              changeClassValue: changeClassValue,
            ),
    );
  }
}

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

  Function changeClassValue;

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

class _textFieldState extends State<textField> {
  final textController = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Row(
        children: [
          Container(
            width: 300.0,
            height: 60.0,
            color: Colors.red,
            child: TextField(
              controller: textController,
            ),
          ),
          RawMaterialButton(
            onPressed: () {
              setState(() {
                widget.changeClassValue();
                print(textController.text);
              });
            },
            child: Icon(Icons.send),
          )
        ],
      ),
    );
  }
}

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

  String text;

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

class _containerState extends State<container> {
  @override
  Widget build(BuildContext context) {
    return Center(
      child: Container(
        width: double.infinity,
        height: 60.0,
        color: Colors.grey,
        child: Text(widget.text),
      ),
    );
  }
}

希望有人能帮助我。

谢谢你:)我写这篇文章是因为否则它不会让我上传它我写这篇文章是因为否则它不会让我上传它我写这篇文章是因为否则它不会让我上传它

Answer 1

您需要将

changeClassValue

的类型更新为

ValueChanged<String>

- 现在您可以在

textField

和

chat

状态之间传递数据。

import 'dart:math';

import 'package:flutter/material.dart';

void main() => runApp(mainApp());

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

class chat extends StatefulWidget {
  const chat({Key? key}) : super(key: key);

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

class _chatState extends State<chat> {
  bool changeClass = false;
  String? text;
  changeClassValue(String? newText) {
    setState(() {
      changeClass = !changeClass;
      text = newText;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: changeClass
          ? container(
              text: text ?? "",
            )
          : textField(
              changeClassValue: changeClassValue,
            ),
    );
  }
}

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

  ValueChanged<String> changeClassValue;

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

class _textFieldState extends State<textField> {
  final textController = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Row(
        children: [
          Container(
            width: 300.0,
            height: 60.0,
            color: Colors.red,
            child: TextField(
              controller: textController,
            ),
          ),
          RawMaterialButton(
            onPressed: () {
               widget.changeClassValue(textController.text);
            },
            child: Icon(Icons.send),
          )
        ],
      ),
    );
  }
}

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

  String text;

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

class _containerState extends State<container> {
  @override
  Widget build(BuildContext context) {
    return Center(
      child: Container(
        width: double.infinity,
        height: 60.0,
        color: Colors.grey,
        child: Text(widget.text),
      ),
    );
  }
}