dart - Flutter - 在路由之间推送和获取值(value)

Question

如何将绿色字符串从 HomePage 页面发送到 ContaPage 页面？

我认为是这样 Navigator.of(context).pushNamed('/conta/green'); 但我不知道如何进入页面 conta green 字符串

因此，通过获取字符串的值，我可以例如更改 ContaPage 中 appBar 的 backgroundColor 的颜色。

ma​​in.dart

import "package:flutter/material.dart";

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: "MyApp",
      home: new HomePage(),
      routes: <String, WidgetBuilder> {
        '/home': (BuildContext context) => new HomePage(),
        '/conta': (BuildContext context) => new ContaPage()
      },
    );
  }
}

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) => new Scaffold(
    appBar: new AppBar(
      backgroundColor: new Color(0xFF26C6DA),
    ),
    body: new ListView  (
      children: <Widget>[
        new FlatButton(
          child: new Text("ok"),
          textColor: new Color(0xFF66BB6A),               
          onPressed: () {
            Navigator.of(context).pushNamed('/conta');
          },
        ),
      ],
    )
  );
}

class ContaPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) => new Scaffold(
    appBar: new AppBar(
      backgroundColor: new Color(0xFF26C6DA),
    ), 
  );
}

Answer 1

您可以按需创建 MaterialPageRoute 并将参数传递给 ContaPage 构造函数。

import "package:flutter/material.dart";

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: "MyApp",
      home: new HomePage(),
    );
  }
}

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) => new Scaffold(
    appBar: new AppBar(
      backgroundColor: new Color(0xFF26C6DA),
    ),
    body: new ListView  (
      children: <Widget>[
        new FlatButton(
          child: new Text("ok"),
          textColor: new Color(0xFF66BB6A),
          onPressed: () {
            Navigator.push(context, new MaterialPageRoute(
              builder: (BuildContext context) => new ContaPage(new Color(0xFF66BB6A)),
            ));
          },
        ),
      ],
    )
  );
}

class ContaPage extends StatelessWidget {
  ContaPage(this.color);
  final Color color;
  @override
  Widget build(BuildContext context) => new Scaffold(
    appBar: new AppBar(
      backgroundColor: color,
    ),
  );
}