- Install
- Set up an editor
- Test drive
- Write your first Flutter app, part 1
- Learn more
- Flutter for Android developers
- Flutter for iOS developers
- Flutter for React Native developers
- Flutter for web developers
- Flutter for Xamarin.Forms developers
- Introduction to declarative UI
- Cookbook
- Codelabs
- Tutorials
- User interface
- Introduction to widgets
- Layouts in Flutter
- Layout tutorial
- Dealing with box constraints
- Adding interactivity to your Flutter app
- Adding assets and images
- Navigation & routing
- Introduction to animations
- Animations overview
- Animations tutorial
- Hero Animations
- Staggered Animations
- Advanced UI
- Slivers
- Taps, drags, and other gestures
- Widget catalog
- Data & backend
- State management
- State management
- Start thinking declaratively
- Differentiate between ephemeral state and app state
- Simple app state management
- List of state management approaches
- JSON and serialization
- Firebase
- Accessibility & internationalization
- Accessibility
- Internationalizing Flutter apps
- Platform integration
- Writing custom platform-specific code
- Packages & plugins
- Using packages
- Developing packages & plugins
- Background processes
- Tools & techniques
- Android Studio / IntelliJ
- Visual Studio Code
- Upgrading Flutter
- Hot reload
- Code formatting
- Debugging Flutter apps
- Using OEM debuggers
- Flutter's build modes
- Testing Flutter apps
- Performance best practices
- Flutter performance profiling
- Creating flavors for Flutter
- Preparing an Android App for Release
- Preparing an iOS App for Release
- Continuous Delivery using fastlane with Flutter
- Bootstrap into Dart
- Inside Flutter
- Platform specific behaviors and adaptations
- Technical Overview
- Technical videos
- FAQ
- Flutter widget index
- Install
- Windows install
- MacOS install
- Linux install
- Set up an editor
- Write your first Flutter app, part 1
- Learn more
- Cupertino (iOS-style) widgets
- Layout widgets
- Animation and motion widgets
- Retrieve the value of a text field
- Basic widgets
- Material Components widgets
- Animate the properties of a Container
- Fade a Widget in and out
- Add a Drawer to a screen
- Displaying SnackBars
- Exporting fonts from a package
- Updating the UI based on orientation
- Using Themes to share colors and font styles
- Using custom fonts
- Working with Tabs
- Building a form with validation
- Create and style a text field
- Focus on a Text Field
- Handling changes to a text field
- Retrieve the value of a text field
- Adding Material Touch Ripples
- Handling Taps
- Implement Swipe to Dismiss
- Display images from the internet
- Fade in images with a placeholder
- Working with cached images
- Basic List
- Create a horizontal list
- Creating a Grid List
- Creating lists with different types of items
- Place a floating app bar above a list
- Working with long lists
- Report errors to a service
- Animating a Widget across screens
- Navigate to a new screen and back
- Navigate with named routes
- Pass arguments to a named route
- Return data from a screen
- Send data to a new screen
- Fetch data from the internet
- Making authenticated requests
- Parsing JSON in the background
- Working with WebSockets
- Persist data with SQLite
- Reading and Writing Files
- Storing key-value data on disk
- Play and pause a video
- Take a picture using the Camera
- An introduction to integration testing
- Performance profiling
- Scrolling
- An introduction to unit testing
- Mock dependencies using Mockito
- An introduction to widget testing
- Finding widgets
- Tapping, dragging and entering text
- Development
- Introduction to widgets
- Layout tutorial
- Dealing with box constraints
- Adding interactivity to your Flutter app
- Adding assets and images
- Navigation & routing
- Navigate to a new screen and back
- Send data to a new screen
- Return data from a screen
- Navigate with named routes
- Animating a Widget across screens
- AnimatedList
- Sample App Catalog
- Animations overview
- Animations tutorial
- Staggered Animations
- Slivers
- Taps, drags, and other gestures
- Accessibility widgets
- Assets, images, and icon widgets
- Async widgets
- Input widgets
- Interaction model widgets
- Painting and effect widgets
- Scrolling widgets
- Styling widgets
- Text widgets
- State management
- Start thinking declaratively
- Differentiate between ephemeral state and app state
- Simple app state management
- List of state management approaches
- JSON and serialization
- Accessibility
- Internationalizing Flutter apps
- Writing custom platform-specific code
- Using packages
- Fetch data from the internet
- Developing packages & plugins
- Background processes
- Android Studio / IntelliJ
- Set up an editor
- Flutter inspector
- Creating Useful Bug Reports
- Visual Studio Code
- Set up an editor
- Upgrading Flutter
- Hot reload
- Code formatting
Pass arguments to a named route
The Navigator
provides the ability to navigate to a named route from any part of an app using a common identifier. In some cases, you may also need to pass arguments to a named route. For example, you may wish to navigate to the /user
route and pass information about the user to that route.
In Flutter, you can accomplish this task by providing additional arguments
to the Navigator.pushNamed
method. You can extract the arguments using the ModalRoute.of
method or inside an onGenerateRoute
function provided to the MaterialApp
or CupertinoApp
constructor.
This recipe demonstrates how to pass arguments to a named route and read the arguments using ModelRoute.of
and onGenerateRoute
.
Directions
- Define the arguments you need to pass
- Create a widget that extracts the arguments
- Register the widget in the
routes
table - Navigate to the widget
1. Define the arguments you need to pass
First, define the arguments you need to pass to the new route. In this example, pass two pieces of data: The title
of the screen and a message
.
To pass both pieces of data, create a class that stores this information.
// You can pass any object to the arguments parameter. In this example, create a
// class that contains both a customizable title and message.
class ScreenArguments {
final String title;
final String message;
ScreenArguments(this.title, this.message);
}
2. Create a widget that extracts the arguments
Next, create a widget that extracts and displays the title
and message
from the ScreenArguments
. To access the ScreenArguments
, use the ModalRoute.of
method. This method returns the current route with the arguments.
// A Widget that extracts the necessary arguments from the ModalRoute.
class ExtractArgumentsScreen extends StatelessWidget {
static const routeName = '/extractArguments';
@override
Widget build(BuildContext context) {
// Extract the arguments from the current ModalRoute settings and cast
// them as ScreenArguments.
final ScreenArguments args = ModalRoute.of(context).settings.arguments;
return Scaffold(
appBar: AppBar(
title: Text(args.title),
),
body: Center(
child: Text(args.message),
),
);
}
}
3. Register the widget in the routes
table
Next, add an entry to the routes
provided to the MaterialApp
Widget. The routes
define which widget should be created based on the name of the route.
MaterialApp(
routes: {
ExtractArgumentsScreen.routeName: (context) => ExtractArgumentsScreen(),
},
);
4. Navigate to the widget
Finally, navigate to the ExtractArgumentsScreen
when a user taps a button using Navigator.pushNamed
. Provide the arguments to the route via the arguments
property. The ExtractArgumentsScreen
extracts the title
and message
from these arguments.
// A button that navigates to a named route that. The named route
// extracts the arguments by itself.
RaisedButton(
child: Text("Navigate to screen that extracts arguments"),
onPressed: () {
// When the user taps the button, navigate to the specific rout
// and provide the arguments as part of the RouteSettings.
Navigator.pushNamed(
context,
ExtractArgumentsScreen.routeName,
arguments: ScreenArguments(
'Extract Arguments Screen',
'This message is extracted in the build method.',
),
);
},
);
Alternatively, extract the arguments using onGenerateRoute
Instead of extracting the arguments directly inside the widget, you can also extract the arguments inside an onGenerateRoute
function and pass them to a widget.
The onGenerateRoute
function creates the correct route based on the given RouteSettings
.
MaterialApp(
// Provide a function to handle named routes. Use this function to
// identify the named route being pushed and create the correct
// Screen.
onGenerateRoute: (settings) {
// If you push the PassArguments route
if (settings.name == PassArgumentsScreen.routeName) {
// Cast the arguments to the correct type: ScreenArguments.
final ScreenArguments args = settings.arguments;
// Then, extract the required data from the arguments and
// pass the data to the correct screen.
return MaterialPageRoute(
builder: (context) {
return PassArgumentsScreen(
title: args.title,
message: args.message,
);
},
);
}
},
);
Complete example
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
// Provide a function to handle named routes. Use this function to
// identify the named route being pushed and create the correct
// Screen.
onGenerateRoute: (settings) {
// If you push the PassArguments route
if (settings.name == PassArgumentsScreen.routeName) {
// Cast the arguments to the correct type: ScreenArguments.
final ScreenArguments args = settings.arguments;
// Then, extract the required data from the arguments and
// pass the data to the correct screen.
return MaterialPageRoute(
builder: (context) {
return PassArgumentsScreen(
title: args.title,
message: args.message,
);
},
);
}
},
title: 'Navigation with Arguments',
home: HomeScreen(),
);
}
}
class HomeScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Home Screen'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
// A button that navigates to a named route that. The named route
// extracts the arguments by itself.
RaisedButton(
child: Text("Navigate to screen that extracts arguments"),
onPressed: () {
// When the user taps the button, navigate to the specific route
// and provide the arguments as part of the RouteSettings.
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => ExtractArgumentsScreen(),
// Pass the arguments as part of the RouteSettings. The
// ExtractArgumentScreen reads the arguments from these
// settings.
settings: RouteSettings(
arguments: ScreenArguments(
'Extract Arguments Screen',
'This message is extracted in the build method.',
),
),
),
);
},
),
// A button that navigates to a named route. For this route, extract
// the arguments in the onGenerateRoute function and pass them
// to the screen.
RaisedButton(
child: Text("Navigate to a named that accepts arguments"),
onPressed: () {
// When the user taps the button, navigate to a named route
// and provide the arguments as an optional parameter.
Navigator.pushNamed(
context,
PassArgumentsScreen.routeName,
arguments: ScreenArguments(
'Accept Arguments Screen',
'This message is extracted in the onGenerateRoute function.',
),
);
},
),
],
),
),
);
}
}
// A Widget that extracts the necessary arguments from the ModalRoute.
class ExtractArgumentsScreen extends StatelessWidget {
static const routeName = '/extractArguments';
@override
Widget build(BuildContext context) {
// Extract the arguments from the current ModalRoute settings and cast
// them as ScreenArguments.
final ScreenArguments args = ModalRoute.of(context).settings.arguments;
return Scaffold(
appBar: AppBar(
title: Text(args.title),
),
body: Center(
child: Text(args.message),
),
);
}
}
// A Widget that accepts the necessary arguments via the constructor.
class PassArgumentsScreen extends StatelessWidget {
static const routeName = '/passArguments';
final String title;
final String message;
// This Widget accepts the arguments as constructor parameters. It does not
// extract the arguments from the ModalRoute.
//
// The arguments are extracted by the onGenerateRoute function provided to the
// MaterialApp widget.
const PassArgumentsScreen({
Key key,
@required this.title,
@required this.message,
}) : super(key: key);
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(title),
),
body: Center(
child: Text(message),
),
);
}
}
// You can pass any object to the arguments parameter. In this example, create a
// class that contains both a customizable title and message.
class ScreenArguments {
final String title;
final String message;
ScreenArguments(this.title, this.message);
}
如果你对这篇内容有疑问,欢迎到本站社区发帖提问 参与讨论,获取更多帮助,或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱,如果其他用户或者作者回复了您的评论,将不能在第一时间通知您!
发布评论