Flutter搜索辅助插件search_helper的使用

search_helper 是一个用于在 Flutter 应用中实现搜索功能的辅助插件。它可以帮助你快速集成搜索功能，并提供一些常见的搜索辅助功能，如自动补全、搜索历史等。

1. 添加依赖

首先，你需要在 pubspec.yaml 文件中添加 search_helper 插件的依赖：

dependencies:
  flutter:
    sdk: flutter
  search_helper: ^1.0.0  # 请使用最新版本

然后运行 flutter pub get 来安装依赖。

2. 基本使用

2.1 初始化 SearchHelper

import 'package:search_helper/search_helper.dart';

final searchHelper = SearchHelper();

2.2 添加搜索历史

你可以使用 addSearchHistory 方法来添加搜索历史记录：

searchHelper.addSearchHistory('Flutter');
searchHelper.addSearchHistory('Dart');

2.3 获取搜索历史

你可以使用 getSearchHistory 方法来获取搜索历史记录：

List<String> history = await searchHelper.getSearchHistory();
print(history);  // 输出: ['Flutter', 'Dart']

2.4 清除搜索历史

你可以使用 clearSearchHistory 方法来清除搜索历史记录：

await searchHelper.clearSearchHistory();

2.5 自动补全

search_helper 还支持自动补全功能。你可以使用 getSuggestions 方法来获取搜索建议：

List<String> suggestions = await searchHelper.getSuggestions('Fl');
print(suggestions);  // 输出: ['Flutter']

3. 示例代码

以下是一个完整的示例，展示如何使用 search_helper 插件实现一个简单的搜索功能：

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

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Search Helper Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: SearchDemo(),
    );
  }
}

class SearchDemo extends StatefulWidget {
  [@override](/user/override)
  _SearchDemoState createState() => _SearchDemoState();
}

class _SearchDemoState extends State<SearchDemo> {
  final searchHelper = SearchHelper();
  final searchController = TextEditingController();
  List<String> searchHistory = [];
  List<String> suggestions = [];

  [@override](/user/override)
  void initState() {
    super.initState();
    _loadSearchHistory();
  }

  Future<void> _loadSearchHistory() async {
    searchHistory = await searchHelper.getSearchHistory();
    setState(() {});
  }

  Future<void> _onSearch(String query) async {
    if (query.isNotEmpty) {
      await searchHelper.addSearchHistory(query);
      setState(() {
        searchHistory.insert(0, query);
      });
    }
  }

  Future<void> _onClearHistory() async {
    await searchHelper.clearSearchHistory();
    setState(() {
      searchHistory.clear();
    });
  }

  Future<void> _onTextChanged(String text) async {
    suggestions = await searchHelper.getSuggestions(text);
    setState(() {});
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Search Helper Demo'),
      ),
      body: Column(
        children: [
          Padding(
            padding: const EdgeInsets.all(8.0),
            child: TextField(
              controller: searchController,
              decoration: InputDecoration(
                labelText: 'Search',
                suffixIcon: IconButton(
                  icon: Icon(Icons.search),
                  onPressed: () => _onSearch(searchController.text),
                ),
              ),
              onChanged: _onTextChanged,
            ),
          ),
          if (suggestions.isNotEmpty)
            Expanded(
              child: ListView.builder(
                itemCount: suggestions.length,
                itemBuilder: (context, index) {
                  return ListTile(
                    title: Text(suggestions[index]),
                    onTap: () {
                      searchController.text = suggestions[index];
                      _onSearch(suggestions[index]);
                    },
                  );
                },
              ),
            ),
          if (searchHistory.isNotEmpty)
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: Text(
                      'Search History',
                      style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
                    ),
                  ),
                  Expanded(
                    child: ListView.builder(
                      itemCount: searchHistory.length,
                      itemBuilder: (context, index) {
                        return ListTile(
                          title: Text(searchHistory[index]),
                          trailing: IconButton(
                            icon: Icon(Icons.delete),
                            onPressed: () async {
                              await searchHelper.removeSearchHistory(searchHistory[index]);
                              setState(() {
                                searchHistory.removeAt(index);
                              });
                            },
                          ),
                        );
                      },
                    ),
                  ),
                  Center(
                    child: TextButton(
                      onPressed: _onClearHistory,
                      child: Text('Clear History'),
                    ),
                  ),
                ],
              ),
            ),
        ],
      ),
    );
  }
}