Flutter谷歌地点搜索插件google_places_flutter_api的使用

Flutter谷歌地点搜索插件google_places_flutter_api的使用

简介

google_places_flutter_api 是一个用于Flutter应用的Google Places自动补全插件。它可以帮助用户在应用中快速查找和选择地点。需要注意的是，使用Google Places API需要在Google Cloud平台上启用计费功能。

安装

在项目的 pubspec.yaml 文件的 dependencies 部分添加以下内容：

dependencies:
  google_places_flutter_api: <latest_version>

请确保将 <latest_version> 替换为最新的版本号。

使用方法

以下是一个完整的示例代码，展示了如何使用 google_places_flutter_api 插件来实现地点搜索功能。

import 'dart:async';
import 'dart:math';

import 'package:google_api_headers/google_api_headers.dart';
import 'package:flutter/material.dart';
import 'package:google_places_flutter_api/google_places_flutter_api.dart';
import 'package:flutter_google_maps_webservices/places.dart';

const kGoogleApiKey = "API_KEY"; // 替换为你的Google API密钥

void main() {
  runApp(const RoutesWidget());
}

final customTheme = ThemeData(
  brightness: Brightness.dark,
  inputDecorationTheme: const InputDecorationTheme(
    border: OutlineInputBorder(
      borderRadius: BorderRadius.all(Radius.circular(4.00)),
    ),
    contentPadding: EdgeInsets.symmetric(
      vertical: 12.50,
      horizontal: 10.00,
    ),
  ),
);

class RoutesWidget extends StatelessWidget {
  const RoutesWidget({Key? key}) : super(key: key);

  [@override](/user/override)
  Widget build(BuildContext context) => MaterialApp(
        title: "My App",
        darkTheme: customTheme,
        themeMode: ThemeMode.dark,
        routes: {
          "/": (_) => const MyApp(),
          "/search": (_) => CustomSearchScaffold(),
        },
      );
}

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

  [@override](/user/override)
  _MyAppState createState() => _MyAppState();
}

final homeScaffoldKey = GlobalKey<ScaffoldState>();
final searchScaffoldKey = GlobalKey<ScaffoldState>();

class _MyAppState extends State<MyApp> {
  Mode? _mode = Mode.overlay;

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      key: homeScaffoldKey,
      appBar: AppBar(
        title: const Text("My App"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            _buildDropdownMenu(),
            ElevatedButton(
              onPressed: _handlePressButton,
              child: const Text("Search places"),
            ),
            ElevatedButton(
              child: const Text("Custom"),
              onPressed: () {
                Navigator.of(context).pushNamed("/search");
              },
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildDropdownMenu() => DropdownButton(
        value: _mode,
        items: const <DropdownMenuItem<Mode>>[
          DropdownMenuItem<Mode>(
            child: Text("Overlay"),
            value: Mode.overlay,
          ),
          DropdownMenuItem<Mode>(
            child: Text("Fullscreen"),
            value: Mode.fullscreen,
          ),
        ],
        onChanged: (dynamic m) {
          setState(() {
            _mode = m;
          });
        },
      );

  void onError(PlacesAutocompleteResponse response) {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text(response.errorMessage!)),
    );
  }

  Future<void> _handlePressButton() async {
    // 显示自动补全输入框并获取用户选择的预测结果
    Prediction? p = await PlacesAutocomplete.show(
      context: context,
      apiKey: kGoogleApiKey,
      onError: onError,
      mode: _mode!,
      language: "fr", // 设置语言为法语
      decoration: InputDecoration(
        hintText: 'Search',
        focusedBorder: OutlineInputBorder(
          borderRadius: BorderRadius.circular(20),
          borderSide: const BorderSide(
            color: Colors.white,
          ),
        ),
      ),
      components: [Component(Component.country, "fr")], // 限制搜索范围为法国
    );

    if (p != null) {
      displayPrediction(p, context);
    }
  }
}

Future<void> displayPrediction(Prediction? p, BuildContext context) async {
  if (p != null) {
    // 获取地点详情（纬度/经度）
    GoogleMapsPlaces _places = GoogleMapsPlaces(
      apiKey: kGoogleApiKey,
      apiHeaders: await const GoogleApiHeaders().getHeaders(),
    );
    PlacesDetailsResponse detail =
        await _places.getDetailsByPlaceId(p.placeId!);
    final lat = detail.result.geometry!.location.lat;
    final lng = detail.result.geometry!.location.lng;

    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text("${p.description} - $lat/$lng")),
    );
  }
}

// 自定义搜索页面，继承自 PlacesAutocompleteWidget
class CustomSearchScaffold extends PlacesAutocompleteWidget {
  CustomSearchScaffold({Key? key})
      : super(
          key: key,
          apiKey: kGoogleApiKey,
          sessionToken: Uuid().generateV4(),
          language: "en", // 设置语言为英语
          components: [Component(Component.country, "uk")], // 限制搜索范围为英国
        );

  [@override](/user/override)
  _CustomSearchScaffoldState createState() => _CustomSearchScaffoldState();
}

class _CustomSearchScaffoldState extends PlacesAutocompleteState {
  [@override](/user/override)
  Widget build(BuildContext context) {
    final appBar = AppBar(title: const AppBarPlacesAutoCompleteTextField());
    final body = PlacesAutocompleteResult(
      onTap: (p) {
        displayPrediction(p, context);
      },
      logo: const Row(
        children: [FlutterLogo()],
        mainAxisAlignment: MainAxisAlignment.center,
      ),
    );
    return Scaffold(key: searchScaffoldKey, appBar: appBar, body: body);
  }

  [@override](/user/override)
  void onResponseError(PlacesAutocompleteResponse response) {
    super.onResponseError(response);
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text(response.errorMessage!)),
    );
  }

  [@override](/user/override)
  void onResponse(PlacesAutocompleteResponse? response) {
    super.onResponse(response);
    if (response != null && response.predictions.isNotEmpty) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text("Got answer")),
      );
    }
  }
}

class Uuid {
  final Random _random = Random();

  String generateV4() {
    // 生成UUID v4格式的字符串
    final int special = 8 + _random.nextInt(4);

    return '${_bitsDigits(16, 4)}${_bitsDigits(16, 4)}-'
        '${_bitsDigits(16, 4)}-'
        '4${_bitsDigits(12, 3)}-'
        '${_printDigits(special, 1)}${_bitsDigits(12, 3)}-'
        '${_bitsDigits(16, 4)}${_bitsDigits(16, 4)}${_bitsDigits(16, 4)}';
  }

  String _bitsDigits(int bitCount, int digitCount) =>
      _printDigits(_generateBits(bitCount), digitCount);

  int _generateBits(int bitCount) => _random.nextInt(1 << bitCount);

  String _printDigits(int value, int count) =>
      value.toRadixString(16).padLeft(count, '0');
}