参数类型“FlutterTagging”不能分配给参数类型“Widget”

Question

我尝试使用外部小部件 (https://github.com/sarbagyastha/flutter_tagging)。我知道，它的保证适用于 android 版本。但是我在 Web 版本中添加它并得到错误“参数类型'FlutterTagging 不能分配给参数类型 Widget`”。它只是简单的代码（例如“Hello, World”，仅此而已）。是不是应该在网页版上工作？

主要代码继承自Widget - 类，源代码清晰。而且我不知道那个错误是什么意思。

    import 'package:flutter_web/material.dart';
    import 'package:flutter_tagging/flutter_tagging.dart';

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

    class MyApp extends StatelessWidget {
      // This widget is the root of your application.
      @override
      Widget build(BuildContext context) {
        return MaterialApp(
          title: 'Flutter Demo',
          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(title),
          ),
          body: Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                Text(
                  'Hello, World!',
                ),
                SingleChildScrollView(
                  child: Column(
                    children: <Widget>[
                      Padding(
                        padding: const EdgeInsets.all(8.0),
                        child:

                        FlutterTagging(
                          textFieldDecoration: InputDecoration(
                              border: OutlineInputBorder(),
                              hintText: "Tags",
                              labelText: "Enter tags"),
                          addButtonWidget: _buildAddButton(),
                          chipsColor: Colors.pinkAccent,
                          chipsFontColor: Colors.white,
                          deleteIcon: Icon(Icons.cancel,color: Colors.white),
                          chipsPadding: EdgeInsets.all(2.0),
                          chipsFontSize: 14.0,
                          chipsSpacing: 5.0,
                          chipsFontFamily: 'helvetica_neue_light',
                          suggestionsCallback: (pattern) async {
                            return await TagSearchService.getSuggestions(pattern);
                          },
                          onChanged: (result) {
                            setState(() {
                              text = result.toString();
                            });
                          },
                        ),
                      ),
                      SizedBox(
                        height: 20.0,
                      ),
                      Center(
                        child: Text(

                          'test',
                          style: TextStyle(color: Colors.pink),
                        ),
                      )
                    ],
                  ),
                ),
              ],
            ),
          ), // This trailing comma makes auto-formatting nicer for build methods.
        );
      }

    }

    Widget _buildAddButton() {
      return Container(
        padding: EdgeInsets.all(8.0),
        decoration: BoxDecoration(
          borderRadius: BorderRadius.all(Radius.circular(20.0)),
          color: Colors.pinkAccent,
        ),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: <Widget>[
            Icon(
              Icons.add,
              color: Colors.white,
              size: 15.0,
            ),
            Text(
              "Add New Tag",
              style: TextStyle(color: Colors.white, fontSize: 14.0),
            ),
          ],
        ),
      );
    }

Answer 1

这是因为在 Flutter Web 中，所有小部件都需要是 package:flutter_web/material.dart 的 Widget 类的子类。而您使用的小部件从package:flutter/material.dart 扩展了Widget 类。由于 Flutter 和 Flutter web 现在是独立的项目，您必须更改源代码以使用 package:flutter_web/material.dart 而不是 package:flutter/material.dart。大多数时候，只需替换 import 语句就可以了。