如何使用 pushNamedAndRemoveUntil 传递参数？

Question

我需要使用 pushNamedAndRemoveUntil 将参数传递到初始页面。我需要重新传递一个带有颜色和 textController.text 的参数到初始页面上的 valueText 和颜色。您需要使用 pushNamedAndRemoveUntil 来执行此操作。请帮助实现此功能。屏幕参数：

class TextValue extends StatefulWidget {
  static const routeName = '/text_value';

  const TextValue({Key? key}) : super(key: key);

  @override
  State<TextValue> createState() => _TextValueState();
}

class _TextValueState extends State<TextValue> {
  // controller for textField
  TextEditingController textController = TextEditingController();

  @override
  void dispose() {
    textController.dispose();
    super.dispose();
  }

  //arg variable
  ColorArguments? arg;

  @override
  Widget build(BuildContext context) {
    //get arg from ColorPickerScreen
    arg ??= ModalRoute.of(context)!.settings.arguments as ColorArguments;

    return Scaffold(
      backgroundColor: arg?.color,
      appBar: AppBar(
        title: const Text('Enter a value'),
        centerTitle: true,
      ),
      body: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 16.0),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            TextFormField(
              controller: textController,
              keyboardType: TextInputType.number,
              inputFormatters: [
                FilteringTextInputFormatter.allow(RegExp(r'(^\d*\.?\d*)'))
              ],
              style: const TextStyle(color: Colors.black),
              decoration: const InputDecoration(
                  hintText: 'Enter a value',
                  enabledBorder: UnderlineInputBorder(
                      borderSide: BorderSide(color: Colors.black, width: 2)),
                  focusedBorder: UnderlineInputBorder(
                      borderSide: BorderSide(color: Colors.black, width: 2))),
            ),
            const SizedBox(height: 20),
            ElevatedButton(
              onPressed: () {
                if (textController.text.isEmpty) {
                } else {
                  Navigator.pushNamedAndRemoveUntil(
                      context, HomeScreen.routeName, (route) => false,
                  );
                }
              },
              child: const Text('Done'),
            )
          ],
        ),
      ),
    );
  }
}

初始屏幕：

import 'package:flutter/material.dart';
import 'package:flutter_app/screens/color_picker_screen.dart';

class HomeScreen extends StatefulWidget {
  final String valueText;
  final ColorArguments? color;
  static const routeName = '/home';

  const HomeScreen({Key? key, required this.valueText, required this.color})
      : super(key: key);

  @override
  State<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  // navigation to the next screen

  void _colorScreen() {
    Navigator.push(context,
        MaterialPageRoute(builder: (context) => const ColorPicker()));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Home'),
        centerTitle: true,
      ),
      body: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 16.0),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            ElevatedButton(
                onPressed: _colorScreen, child: const Text('Choose a color')),
            const SizedBox(height: 30.0),
            TextFormField(
              readOnly: true,
              initialValue: widget.valueText,
            ),
            const SizedBox(height: 100),
            Container(
              width: 50,
              height: 50,
              color: widget.color?.color,
            ),
          ],
        ),
      ),
    );
  }
}

Answer 1

你为什么不考虑使用 Class 构造函数并像这样传递数据

Navigator.push(context,
    MaterialPageRoute(builder: (context) => const ColorPicker(<Your_data>)));

Answer 2

您可以使用 pushNamedAndRemoveUntil 方法的命名 arguments 参数。您需要做的就是创建一个自定义对象，用于将您需要的所有值传递给推送调用。可以在初始屏幕中使用

访问参数

final args = ModalRoute.of(context)!.settings.arguments

您可以参考 this Flutter cookbook 关于使用带参数的命名路由的导航。

如何使用 pushNamedAndRemoveUntil 传递参数？

How to pass parameters using pushNamedAndRemoveUntil?

dart

flutter