Navigator 传递数据

1、

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
 
class Todo {
  final String title;
  final String description;
 
  Todo(this.title, this.description);
}
 
void main() {
  runApp(MaterialApp(
    title: 'Passing Data',
    home: TodosScreen(
      todos: List.generate(
        20,
        (i) => Todo(
              'Todo $i',
              'A description of what needs to be done for Todo $i',
            ),
      ),
    ),
  ));
}
 
class TodosScreen extends StatelessWidget {
  final List<Todo> todos;
 
  TodosScreen({Key key, @required this.todos}) : super(key: key);
 
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Todos'),
      ),
      body: ListView.builder(
        itemCount: todos.length,
        itemBuilder: (context, index) {
          return ListTile(
            title: Text(todos[index].title),
            // When a user taps on the ListTile, navigate to the DetailScreen.
            // Notice that we're not only creating a DetailScreen, we're
            // also passing the current todo through to it!
            onTap: () {
              Navigator.push(
                context,
                MaterialPageRoute(
                  builder: (context) => DetailScreen(todo: todos[index]),
                ),
              );
            },
          );
        },
      ),
    );
  }
}
 
class DetailScreen extends StatelessWidget {
  // Declare a field that holds the Todo
  final Todo todo;
 
  // In the constructor, require a Todo
  DetailScreen({Key key, @required this.todo}) : super(key: key);
 
  @override
  Widget build(BuildContext context) {
    // Use the Todo to create our UI
    return Scaffold(
      appBar: AppBar(
        title: Text(todo.title),
      ),
      body: Padding(
        padding: EdgeInsets.all(16.0),
        child: Text(todo.description),
      ),
    );
  }
}

2、

import 'package:flutter/material.dart';
// 引入新页面
import 'page.dart';
 
void main() => runApp(MyApp());
 
class MyApp extends StatelessWidget {
 
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      // 处理Named页面跳转 传递参数
      onGenerateRoute: (RouteSettings setting) {
        if(setting.name == '/page') {
          return MaterialPageRoute(builder: (context) => Page(id: setting.arguments['id']));
        }
      },
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}
 
class MyHomePage extends StatelessWidget {
  MyHomePage({Key key, this.title}) : super(key: key);
  final String title;
 
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(this.title),
      ),
      body: Center(
        child: GestureDetector(
          onTap: (){
            // 进行Named页面跳转 传递参数
            Navigator.pushNamed(context, '/page', arguments: { "id": 1} );
          },
          child: Text("go next page with params"),
        ),
      ),
    );
  }
}

 3、页面接受参数 page.dart

import 'package:flutter/material.dart';
 
class Page extends StatelessWidget{
  Page({this.id});
  final int id;
 
  @override
  Widget build(BuildContext context) {
    return Material(
      child: Center(
        child: Text("hi this is next page, id is $id"),
      ),
    );
  }
}