Question

我正在制作一个词汇应用程序，并且在如下数据中包含List<Map<String, String>>。

english.dart

class Service {
  static List<Map<String, String>> getSuggestions(String query) {
    List<Map<String, String>> matches = List<Map<String, String>>();
    matches.addAll(words);

    matches.retainWhere(
        (s) => s['word'].toLowerCase().startsWith(query.toLowerCase()));
    return matches;
  }

  static final List<Map<String, String>> words = [
    {'word': "aardvark", 'meaning': "땅돼지"},
    ...
  ];
}

home.dart

import 'package:flutter_typeahead/flutter_typeahead.dart';

class _HomeState extends State<Home> {
SuggestionsBoxController suggestionsBoxController =
      SuggestionsBoxController();
final TextEditingController _controller = TextEditingController();
  var _controller2 = TextEditingController();

void displayBottomSheet(BuildContext context) {
    showModalBottomSheet(
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.vertical(
            top: Radius.circular(40),
          ),
        ),
        context: context,
        isScrollControlled: true,
        backgroundColor: Colors.white,
        isDismissible: true,
        builder: (context) {
          return StatefulBuilder(
              builder: (BuildContext context, StateSetter state) {
            return Form(
                key: this._formKey,
                child: Container(
                    height: MediaQuery.of(context).size.height -
                        190.0, 
                    child: Column(
                      children: <Widget>[
                        Padding(
                            padding: EdgeInsets.only(top: 10, left: 280),
                            child: FlatButton(
                                child: Text('save',
                                    style: TextStyle(
                                        fontSize: 20,
                                        fontWeight: FontWeight.w800)),
                                onPressed: () {
                                  setState(() {
                                    saveDB();
                                    _controller.clear();
                                    _controller2.clear();
                                    FocusScope.of(context)
                                        .requestFocus(focusNode1);
                                  });
                                })),
                        Container(
                            margin: EdgeInsets.only(left: 20, right: 20),
                            child: Column(children: <Widget>[
                              Focus(
                                child: TypeAheadFormField(
                                  suggestionsBoxController:
                                      suggestionsBoxController,
                                  hideOnEmpty: true,
                                  textFieldConfiguration:
                                      TextFieldConfiguration(
                                          maxLines: null,
                                          onChanged: (text) {
                                            setState(() {
                                              this.word = this._controller.text;
                                            });
                                          },
                                          focusNode: focusNode1,
                                          autofocus: true,
                                          controller: this._controller,
                                          style: TextStyle(
                                              fontSize: 30,
                                              fontWeight: FontWeight.w800,
                                              color: Colors.black),
                                          decoration: InputDecoration(
                                            isDense: true,
                                            suffix: Padding(
                                                padding:
                                                    const EdgeInsetsDirectional
                                                        .only(),
                                                child: IconButton(
                                                  onPressed: () =>
                                                      _controller.clear(),
                                                  icon: Icon(Icons.clear),
                                                  iconSize: 25,
                                                  color: Colors.black
                                                      .withOpacity(0.5),
                                                )),
                                            contentPadding: EdgeInsets.only(
                                                left: 11, bottom: 3),
                                            enabledBorder: UnderlineInputBorder(
                                                borderSide: BorderSide(
                                                    color: Colors.black)),
                                            focusedBorder: UnderlineInputBorder(
                                              borderSide: BorderSide(
                                                  color: Colors.black),
                                            ),
                                            hintText: "word",
                                            hintStyle: TextStyle(
                                                fontSize: 29.0,
                                                color: Colors.black
                                                    .withOpacity(0.5)),
                                          )),
                                  suggestionsBoxVerticalOffset: 0,
                                  suggestionsBoxDecoration:
                                      SuggestionsBoxDecoration(
                                          constraints:
                                              BoxConstraints(maxHeight: 124),
                                          offsetX: 0,
                                          elevation: 10,
                                          color: Colors.white,
                                          borderRadius: BorderRadius.only(
                                              bottomLeft: Radius.circular(30),
                                              bottomRight:
                                                  Radius.circular(30))),
                                  suggestionsCallback: (pattern) {
                                    if (pattern.length > 0) {
                                      return Service.getSuggestions(pattern);
                                    }
                                  },
                                  itemBuilder: (context, suggestion) {
                                    return Container(
                                        decoration: new BoxDecoration(),
                                        child: ListTile(
                                            dense: true,
                                            contentPadding:
                                                EdgeInsets.only(left: 20),
                                            title: Row(children: <Widget>[
                                              Text(suggestion['word'],
                                                  style: TextStyle(
                                                      fontSize: 18,
                                                      fontWeight:
                                                          FontWeight.w500)),
                                              SizedBox(width: 7),
                                              Text(suggestion['meaning'],
                                                  style: TextStyle(
                                                      fontSize: 18,
                                                      fontWeight:
                                                          FontWeight.w300))
                                            ])));
                                  },
                                  transitionBuilder:
                                      (context, suggestionsBox, controller) {
                                    return suggestionsBox;
                                  },
                                  onSuggestionSelected: (suggestion) {
                                    this._controller.text = suggestion['word'];
                                    this.word = this._controller.text;
                                    this._controller2.text =
                                        suggestion['meaning'];

                                    FocusScope.of(context)
                                        .requestFocus(focusNode2);
                                  },
                                 
                                  onSaved: (value) =>
                                      this._selectedWord = value,
                                ),
                              ),
                              TextField(
                                  maxLines: null,
                                  controller: _controller2,
                                  focusNode: focusNode2,
                                  textInputAction: TextInputAction.done,
                                  onChanged: (String meaning) {
                                    this.meaning = meaning;
                                  },
                                  style: TextStyle(
                                      fontSize: 20,
                                      fontWeight: FontWeight.w500,
                                      color: Colors.black),
                                  decoration: new InputDecoration(
                                      isDense: true,
                                      suffix: Padding(
                                          padding:
                                              const EdgeInsets.only(left: 20),
                                          child: IconButton(
                                            onPressed: () =>
                                                _controller2.clear(),
                                            icon: Icon(Icons.clear),
                                            color:
                                                Colors.black.withOpacity(0.5),
                                          )),
                                      contentPadding:
                                          EdgeInsets.only(left: 13, bottom: 20),
                                      border: InputBorder.none,
                                      focusedBorder: InputBorder.none,
                                      enabledBorder: InputBorder.none,
                                      hintText: "meaning",
                                      hintStyle: TextStyle(
                                          color:
                                              Colors.black.withOpacity(0.5)))),
                            ]))
                      ],
                    )));
          });
        });
  }

我在文本字段中使用了typeahead plugin，但是没有用。但是在VSCode中，我的代码没有错误。我该怎么解决？

Answer 1

我做了一点测试，它对我有用。这是我的代码：

Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            TypeAheadField(
              textFieldConfiguration: TextFieldConfiguration(
                  autofocus: true,
                  style: DefaultTextStyle.of(context).style.copyWith(
                      fontStyle: FontStyle.italic
                  ),
                  decoration: InputDecoration(
                      border: OutlineInputBorder()
                  )
              ),
              suggestionsCallback: (pattern) {
                return Service.getSuggestions(pattern);
              },
              itemBuilder: (context, suggestion) {
                return ListTile(
                  title: Text(suggestion['word']),
                  subtitle: Text('\$${suggestion['meaning']}'),
                );
              },
              onSuggestionSelected: (suggestion) {
                Navigator.of(context).push(MaterialPageRoute(
                    builder: (context) => null
                ));
              },
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: null,
        tooltip: 'fd',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }

这是课程服务：

class Service {
  static List<Map<String, String>> getSuggestions(String query) {
    List<Map<String, String>> matches = List<Map<String, String>>();
    matches.addAll(words);

    matches.retainWhere(
            (s) => s['word'].toLowerCase().startsWith(query.toLowerCase()));

    return matches;
  }

  static final List<Map<String, String>> words = [
    {'word': "aardvark", 'meaning': "땅돼지"},
    {'word': "bbdaad", 'meaning': "땅돼지지"},
  ];
}

希望它可以为您提供帮助

List <String>不是'function result'的List <Map <String，String>类型的子类型

1 个答案: