如何将非字符串数据传递给Flutter中的命名路由？

问题描述 投票：29回答：7

我有很多屏幕，我正在使用Navigator。我想使用“命名路由”，但我还需要将非字符串（如图像）传递给下一个路由。

我不能使用pushNamed()因为我无法将非字符串数据传递给它。

如何使用命名路由+发送非字符串数据？

dart flutter
7个回答
41
投票

编辑：

现在可以将复杂的参数传递给Navigator.pushNamed：

String id;
Navigator.pushNamed(context, '/users', arguments: id);

然后可以在onGenerateRoute中使用它来使用以下参数自定义路径构建：

MaterialApp(
  title: 'Flutter Hooks Gallery',
  onGenerateRoute: (settings) {
    final arguments = settings.arguments;
    switch (settings.name) {
      case '/users':
        if (arguments is String) {
          // the details page for one specific user
          return UserDetails(arguments);
        }
        else {
          // a route showing the list of all users
          return UserList();
        }
      default:
        return null;
    }
  },
);
3
投票

使用onGenerateRoute很容易通过Navigator.pushNamed或Navigator.pushReplacementNamed传递路由转换的复杂参数

显示概念的最小设置将是

main.dart

import 'package:flutter/material.dart';
import 'package:navigator/routes.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Navigation Demo',
      theme: ThemeData(
        primarySwatch: Colors.teal,
      ),
      onGenerateRoute: (RouteSettings settings) {
        return MaterialPageRoute(
          builder: (BuildContext context) => makeRoute(
                context: context,
                routeName: settings.name,
                arguments: settings.arguments,
              ),
          maintainState: true,
          fullscreenDialog: false,
        );
      },
    );
  }
}

routes.dart

在_buildRoute方法中，我们检查路由名称并将参数转换为所需类型。

缺点是，如果必需参数不是简单类型，则必须事先定义类型。

import 'package:flutter/material.dart';

import 'package:navigator/list.dart';
import 'package:navigator/details.dart';

Widget makeRoute(
    {@required BuildContext context,
    @required String routeName,
    Object arguments}) {
  final Widget child =
      _buildRoute(context: context, routeName: routeName, arguments: arguments);
  return child;
}

Widget _buildRoute({
  @required BuildContext context,
  @required String routeName,
  Object arguments,
}) {
  switch (routeName) {
    case '/':
      return ArticleList();
    case '/ArticleView':
      Article article = arguments as Article;
      return ArticleView(article: article);
    default:
      throw 'Route $routeName is not defined';
  }
}

查看

list.dart

在我们的例子中使用定义的类型Article构造路由参数。

import 'package:flutter/material.dart';
import 'package:navigator/details.dart' show Article;

class ArticleList extends StatefulWidget {
  @override
  _ArticleListState createState() => _ArticleListState();
}

class _ArticleListState extends State<ArticleList> {
  List<Article> articles = [
    Article(
        id: 1,
        title: 'Article 1',
        author_name: 'Nilotpal',
        summary: 'Article 1 summary'),
    Article(
        id: 2,
        title: 'Article 2',
        author_name: 'Mike',
        summary: 'Article 2 summary'),
  ];
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Articles'),
      ),
      body: Center(
        child: Column(
          children: <Widget>[
            ListTile(
              title: Text('${articles[0].title}'),
              subtitle: Text('by ${articles[0].author_name}'),
              onTap: () {
                Navigator.of(context)
                    .pushNamed('/ArticleView', arguments: articles[0]);
              },
            ),
            ListTile(
              title: Text('${articles[1].title}'),
              subtitle: Text('by ${articles[1].author_name}'),
              onTap: () {
                Navigator.of(context)
                    .pushNamed('/ArticleView', arguments: articles[1]);
              },
            ),
          ],
        ),
      ),
    );
  }
}

details.dart

定义参数的类型

import 'package:flutter/material.dart';

class Article {
  final int id;
  final String author_name;
  final String title;
  final String summary;

  Article(
      {@required this.id,
      @required this.author_name,
      @required this.title,
      @required this.summary});
}

class ArticleView extends StatelessWidget {
  final Article _article;

  ArticleView({@required Article article}) : _article = article;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('${_article.title}'),
      ),
      body: SafeArea(
        top: true,
        child: Center(
          child: Column(
            children: <Widget>[
              Text('${_article.author_name}'),
              Text('${_article.summary}'),
            ],
          ),
        ),
      ),
    );
  }
}
2
投票

Flutter Cookbook显示了如何导航到新页面并将非字符串数据传递给它。

Passing data to next page

我从Navigator.pushedNamed()开始，因为它很简单，我没有任何数据可以通过。当我的需求发生变化并且我想传递数据时，我切换到了Navigator.push()。

例：

var nextPageData = {foo:'bar'};

Navigator.push(
  context,
  MaterialPageRoute(builder: (context) => 
     MyNextPage(myData: nextPageData))
 );
1
投票

对于这个问题的结果，我开发了这个包

链接：https://pub.dartlang.org/packages/navigate

这提供了很多你期望和易于使用

Navigate.navigate(context,
                      "home",
                      transactionType:TransactionType.fromLeft , // optional
                      replaceRoute: ReplaceRoute.thisOne, //optional
                      arg: {"transactionType":TransactionType.fromLeft,"replaceRoute":ReplaceRoute.thisOne} //optional
                      );
1
投票

您可以使用应用程序的参数routes直接传递参数。

像这样：

  routes: {
    HomePage.route: (_) => HomePage(),
    DetailsPage.route: (context) =>
        DetailsPage(ModalRoute.of(context).settings.arguments),
  },

在这种情况下，完整的示例将如下所示：

import 'package:flutter/material.dart';

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

    class MyApp extends StatelessWidget {
      @override
      Widget build(BuildContext context) {
        return MaterialApp(
          title: 'Flutter Demo',
          initialRoute: HomePage.route,
          routes: {
            HomePage.route: (_) => HomePage(),
            DetailsPage.route: (context) =>
                DetailsPage(ModalRoute.of(context).settings.arguments),
          },
        );
      }
    }

    class HomePage extends StatelessWidget {
      static const String route = '/';

      @override
      Widget build(BuildContext context) {
        return Scaffold(
          body: Container(),
          floatingActionButton: FloatingActionButton(
            onPressed: () {
              Navigator.pushNamed(context, '/details',
                  arguments: ScreenArguments(
                    'My Details',
                    'Some Message',
                  ));
            },
          ),
        );
      }
    }

    class DetailsPage extends StatelessWidget {
      static const String route = '/details';

      final ScreenArguments arguments;

      DetailsPage(this.arguments);

      @override
      Widget build(BuildContext context) {
        return Scaffold(
          appBar: AppBar(
            title: Text(arguments.title),
          ),
          body: Center(
            child: Text(arguments.message),
          ),
        );
      }
    }

    class ScreenArguments {
      final String title;
      final String message;

      ScreenArguments(this.title, this.message);
    }
0
投票

我正在用相机拍摄图像，然后将它们传递到确认页面，如下所示：

   ImagePicker.pickImage(source: source).then((File file) {
    Navigator.push(
        context,
        MaterialPageRoute(
          builder: (context) => MediaCaptured(file: file),
        ));
  });

您可以轻松地对任何类型的文件或非字符串数据执行相同操作。

var foo = "non-string data";
Navigator.push(
        context,
        MaterialPageRoute(
          builder: (context) => MediaCaptured(foo: foo),
        ));

如上所述，通过它的类名调用路径中的下一页。

只需确保您的新页面在其构造函数中接受此内容即可。

 // Stateful Widget
class MediaCaptured extends StatefulWidget {
    MediaCaptured({ Key key, @required this.foo,}) : super(key: key);
    final var foo;
}

// StatelessWidget
class MediaCaptured extends StatelessWidget {
    MediaCaptured(this.foo);
    var foo;
}
-4
投票
We can pass any type of arguments when declaring routes as constructor arguments as below,

For example to send a list of Strings,

List<String> titles = [];

void main() => runApp(
      new MaterialApp(
        home: new FirstPage(),
        routes: <String, WidgetBuilder>{
          "/SecondPage": (BuildContext context) => new SecondPage(titles),
        },
      ),
    );

class FirstPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Container(
      child: new RaisedButton(onPressed: () {
        Navigator.of(context).pushNamed('/SecondPage');
      }),
    );
  }
}

class SecondPage extends StatelessWidget {
  final List<String> titles;

  SecondPage(this.titles);

  @override
  Widget build(BuildContext context) {
    return new ListView.builder(
      itemBuilder: (context, index) {
        return new ListTile(
          title: new Text(titles[index]),
        );
      },
    );
  }
}
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