flutter - 提前振颤

Question

使用typeahead软件包时，我没有得到期望的结果。
当前的不良行为:

当我点击文本字段时，我什至在开始输入之前就立即显示所有建议的列表(超过26,000条)

当我开始输入内容时，建议列表不会调整(例如，如果我输入“a”，则会显示建议的完整列表，并且列表不会进行过滤，仅显示以“a”开头的建议

期望的结果:

我只是希望该功能根据输入的内容向我显示建议-我确信我的代码实现有误，我将非常感谢您的帮助!

我的相关代码:

import 'package:flutter/material.dart';
import 'package:flutter_typeahead/flutter_typeahead.dart';

import '../providers/analysis_route_provider.dart';

class AutoCompleteTextfieldTwo extends StatefulWidget {
  @override
  _AutoCompleteTextfieldTwoState createState() =>
      _AutoCompleteTextfieldTwoState();
}

class _AutoCompleteTextfieldTwoState extends State<AutoCompleteTextfieldTwo> {
  final TextEditingController _controller = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return TypeAheadField(
      hideOnEmpty: true,
      textFieldConfiguration: TextFieldConfiguration(
        style: TextStyle(
          color: Colors.white,
        ),
        autofocus: false,
        controller: this._controller,
        keyboardType: TextInputType.text,
        enabled: true,
        focusNode: FocusNode(),
        decoration: InputDecoration(
          border: OutlineInputBorder(
            borderRadius: BorderRadius.circular(20),
            borderSide: BorderSide(
              width: 2,
              color: Colors.blue,
            ),
          ),
          hintText: 'Type in company name or ticker symbol',
          hintStyle: TextStyle(
            color: Colors.grey,
          ),
        ),
      ),
      getImmediateSuggestions: true,
      hideOnError: true,
      suggestionsCallback: (pattern) async {
        return await AnalysisRouteProvider.getCompaniesForTextfield2(pattern);
      },
      itemBuilder: (context, itemData) {
        return ListTile(
          title: Text(itemData['name'].toString()),
          subtitle: Text(itemData['symbol'].toString()),
        );
      },
      onSuggestionSelected: (suggestion) {
        print('selected');

        FocusNode().unfocus();
        this._controller.text = suggestion['name'].toString();
        _controller.clear();
      },
    );
  }
}

Http请求:

 static Future getCompaniesForTextfield2(String query) async {
    var url = *url with api key here*;
    http.Response response = await http.get(url, headers: {
      'Content-Type': 'application/json',
    });
    var jsonData = json.decode(response.body);

    return jsonData;
  }

JSON代码段(从API实际返回的对象超过26,000个):

[ {
  "symbol" : "SPY",
  "name" : "SPDR S&P 500",
  "price" : 326.7,
  "exchange" : "NYSE Arca"
}, {
  "symbol" : "CMCSA",
  "name" : "Comcast Corp",
  "price" : 41.98,
  "exchange" : "Nasdaq Global Select"
}, {
  "symbol" : "KMI",
  "name" : "Kinder Morgan Inc",
  "price" : 11.83,
  "exchange" : "New York Stock Exchange"
}]

我也确定这部分信息是相关的。当前，当我调试并点击“预输入”文本字段时，在调试控制台中得到以下信息:

W/IInputConnectionWrapper(13704): beginBatchEdit on inactive InputConnection
W/IInputConnectionWrapper(13704): getTextBeforeCursor on inactive InputConnection
W/IInputConnectionWrapper(13704): getTextAfterCursor on inactive InputConnection
W/IInputConnectionWrapper(13704): getSelectedText on inactive InputConnection
W/IInputConnectionWrapper(13704): endBatchEdit on inactive InputConnection

Answer 1

我认为您应该在getImadiateSugetions上设置false以禁用onTap上显示建议列表。
关于第二个问题，您不会得到建议，我认为问题出在json中，
您正在使用json.decode，它将解码[]中要列出的任何json，如果是{}则将其解码到map中，因此我认为您应该做的是:

suggestionsCallback: (pattern) async {
        var list = await AnalysisRouteProvider.getCompaniesForTextfield2(pattern);
        return list[0];
      },