Flutter：自动完成文本字段不适用于自定义数据类型

Question

我正在尝试构建一个具有自动完成功能的文本字段。我正在使用 AutoComplete TextField 包。

我的用户模型 class 具有 fromMap 和 toMap 方法。有从数据库和 returns 用户列表 List<Users> 中检索用户的功能。

这是构建自动完成字段的代码：

AutoCompleteTextField searchTextField = AutoCompleteTextField<Users>(
    key: key,
    clearOnSubmit: false,
    suggestions: users,
    style: TextStyle(color: Colors.black, fontSize: 16.0),
    decoration: InputDecoration(
      contentPadding: EdgeInsets.fromLTRB(10.0, 30.0, 10.0, 20.0),
      hintText: "Search Name",
      hintStyle: TextStyle(color: Colors.black),
    ),
    itemFilter: (item, query) {
      return item.name.toLowerCase().startsWith(query.toLowerCase());
    },
    itemSorter: (a, b) {
      return a.name.compareTo(b.name);
    },
    itemSubmitted: (item) {
      setState(() {
        searchTextField.textField.controller.text = item.name;
      });
    },
    itemBuilder: (context, item) {
      return Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: <Widget>[
          Text(
            item.name,
          ),
        ],
      );
    },
  );

问.我是不是遗漏了什么或做错了什么？

注意：

users 对象具有正确格式的用户列表，我已打印以验证这一点。

Answer 1

正如@pskink 提到的，

you are using autocomplete_textfield? i had a lot of problems with it, that disappeared when i switched to flutter_typeahead (much better documented package)

所以我考虑了他的建议，并转向 flutter_typeahead 包。

final TextEditingController _typeAheadController = TextEditingController();

List<String> usersList;

//find and create list of matched strings
List<String> _getSuggestions(String query) {
    List<String> matches = List();

    matches.addAll(usersList);

    matches.retainWhere((s) => s.toLowerCase().contains(query.toLowerCase()));
    return matches;
}

//gets user list from db
void _getUsersList() async {
    usersList = await databaseHelper.getUsersList();
}


//the above code is defined in the class, before build method


//builds the text field
TypeAheadFormField(
  textFieldConfiguration: TextFieldConfiguration(
      controller: _typeAheadController,
      decoration: InputDecoration(labelText: 'Select a User'),
  suggestionsCallback: (pattern) {
    return _getSuggestions(pattern);
  },
  itemBuilder: (context, suggestion) {
    return ListTile(
      title: Text(suggestion),
    );
  },
  transitionBuilder: (context, suggestionsBox, controller) {
    return suggestionsBox;
  },
  onSuggestionSelected: (suggestion) {
    _typeAheadController.text = suggestion;

  },
  validator: (val) => val.isEmpty
      ? 'Please select a user...'
      : null,
  onSaved: (val) => setState(() => _name = val),
),



//function that pulls data from db and create a list, defined in db class
//not directly relevant but it may help someone
Future<List<String>> getUsersList() async {
    Database db = await instance.database;

    final usersData = await db.query("users");

    return usersData.map((Map<String, dynamic> row) {
      return row["name"] as String;
    }).toList();
}

PS: 关于 autocomplete_textfield 我怀念的一件事是我们可以传递多个参数的方式，因为我们可以从我们自己的自定义模型继承例如 user 模型。我知道这是可能的，但我是新手，所以仍然无法让它发挥作用！ :(

Answer 2

我遇到了同样的问题，解决方案是放置一个布尔值并显示一个 CircularProgressIndicator，直到加载列表中的所有数据，从而呈现 AutoCompleteTextField

例如：


  _isLoading
                   ? CircularProgressIndicator ()
                   : searchTextField = AutoCompleteTextField <User> (your component here)

Flutter：自动完成文本字段不适用于自定义数据类型

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