type '(String) => dynamic' 不是 'Widget' 类型的子类型

Question

我正在尝试使用命名路由导航到页面。

主文件中的路由：

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'FlutterShare',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.deepPurple,
        accentColor: Colors.teal,
      ),
      home: Home(),
      routes: {
        '/search': (BuildContext context) => Search(),
      },
    );
  }
}

正在推送页面：

class HomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        centerTitle: true,
        title: Text('BookClub'),
        actions: [
          IconButton(
              icon: Icon(Icons.add),
              onPressed: () {
                Navigator.of(context).pushNamed('/search');
              })
        ],
      ),
      drawer: AppDrawer(),
    );
  }
}

错误：

type '(String) => dynamic' is not a subtype of type 'Widget'
The relevant error-causing widget was
  Search                            lib\main.dart:21

这是我第一次构建应用程序，我没有找到解决方案。 main.dart 文件中的路由错误。

搜索码：

class Search extends StatefulWidget {
  @override
  _SearchState createState() => _SearchState();
}

class _SearchState extends State<Search> {
  TextEditingController searchController = TextEditingController();
  Future<QuerySnapshot> searchResultsFuture;

      
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Theme.of(context).primaryColor.withOpacity(0.8),
      appBar: buildSearchField(),
      body: buildNoContent()
    );
  }
}

  AppBar buildSearchField() {
    return AppBar(
      backgroundColor: Colors.white,
      title: TextFormField(
        controller: searchController,
        decoration: InputDecoration(
          hintText: "Search for a book",
          filled: true,
          prefixIcon: Icon(
            Icons.account_box,
            size: 28.0,
          ),
          suffixIcon: IconButton(
            icon: Icon(Icons.clear),
            onPressed: null,
          ),
        ),
        onFieldSubmitted: null,
      ),
    );
  }

  Container buildNoContent() {
    final Orientation orientation = MediaQuery.of(context).orientation;
    return Container(
      child: Center(
        child: ListView(
          shrinkWrap: true,
          children: <Widget>[
            SvgPicture.asset(
              'assets/images/search.svg',
              height: orientation == Orientation.portrait ? 300.0 : 200.0,
            ),
            Text(
              "Find Users",
              textAlign: TextAlign.center,
              style: TextStyle(
                color: Colors.white,
                fontStyle: FontStyle.italic,
                fontWeight: FontWeight.w600,
                fontSize: 60.0,
              ),
            ),
          ],
        ),
      ),
    );
  }

希望这对您有所帮助。我在过去的 3 个小时里一直被困在这个问题上，找不到任何解决办法。

Answer 1

main.dart。您必须将起始页添加到 initialRoute。您可以删除 'home' 参数。

    initialRoute: HomeScreen(),
    routes: {
              "/search" (context) => Search()
          },

因此，home.dart 归档；

Navigator.of(context).pushNamed('/search');

type '(String) => dynamic' 不是 'Widget' 类型的子类型

type '(String) => dynamic' is not a subtype of type 'Widget'

flutter

dart

flutter-navigation