Flutter增强现实定位插件ar_location_view的使用

插件简介

ar_location_view 是一个用于地理定位的增强现实（AR）Flutter插件。它受到HDAugmentedReality的启发，设计用于在静态兴趣点（POIs）密集的区域提供所有POIs的最大可见性。该插件忽略了POIs的高度，并具有以下特性：

• 自动垂直堆叠注解视图
• 跟踪用户移动并更新可见的注解
• 完全可定制的注解视图
• 支持所有旋转方向

基本使用方法

添加依赖

首先，在pubspec.yaml文件中添加ar_location_view作为依赖项。

dependencies:
  ar_location_view: ^latest_version

然后运行flutter pub get来安装插件。

配置权限

iOS配置

在Info.plist文件中添加以下键值对以请求相机和位置权限：

<key>NSLocationWhenInUseUsageDescription</key>
<string>We need your location to show POIs around you.</string>
<key>NSCameraUsageDescription</key>
<string>We need access to your camera to provide AR experience.</string>

同时在Podfile中添加如下代码：

post_install do |installer|
  installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] ||= [
        '$(inherited)',
        'PERMISSION_CAMERA=1',
        'PERMISSION_LOCATION=1',
        'PERMISSION_SENSORS=1',   
      ]
    end 
  end
end

Android配置

在AndroidManifest.xml中添加必要的权限：

<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.RECORD_AUDIO"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

创建自定义注解类

根据需求创建一个继承自ArAnnotation的类，例如：

class Annotation extends ArAnnotation {
  final AnnotationType type;
  
  Annotation({required super.uid, required super.position, required this.type});
}

创建注解视图组件

为每个注解创建一个自定义的Widget，如下面的例子所示：

class AnnotationView extends StatelessWidget {
  const AnnotationView({
    Key? key,
    required this.annotation,
  }) : super(key: key);

  final Annotation annotation;

  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: BoxDecoration(
        borderRadius: BorderRadius.circular(5),
        color: Colors.white,
      ),
      child: Row(
        children: [
          Expanded(
            child: Container(
              decoration: const BoxDecoration(
                borderRadius: BorderRadius.only(
                  topLeft: Radius.circular(5),
                  bottomLeft: Radius.circular(5),
                ),
              ),
              child: typeFactory(annotation.type),
            ),
          ),
          Expanded(
            flex: 2,
            child: Padding(
              padding: const EdgeInsets.all(4.0),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: [
                  Text(
                    annotation.type.toString().substring(15),
                    maxLines: 1,
                    style: const TextStyle(fontWeight: FontWeight.bold),
                  ),
                  Text(
                    '${annotation.distanceFromUser.toInt()} m',
                  ),
                ],
              ),
            ),
          )
        ],
      ),
    );
  }

  Widget typeFactory(AnnotationType type) {
    IconData iconData = Icons.ac_unit_outlined;
    Color color = Colors.teal;
    switch (type) {
      case AnnotationType.pharmacy:
        iconData = Icons.local_pharmacy_outlined;
        color = Colors.red;
        break;
      case AnnotationType.hotel:
        iconData = Icons.hotel_outlined;
        color = Colors.green;
        break;
      case AnnotationType.library:
        iconData = Icons.library_add_outlined;
        color = Colors.blue;
        break;
    }
    return Icon(
      iconData,
      size: 40,
      color: color,
    );
  }
}

使用ArLocationWidget

最后，在你的应用程序中使用ArLocationWidget来显示增强现实视图。这里给出一个完整的示例：

import 'package:ar_location_view_example/annotation_view.dart';
import 'package:ar_location_view_example/annotations.dart';
import 'package:flutter/material.dart';
import 'package:ar_location_view/ar_location_view.dart';
import 'package:geolocator/geolocator.dart';

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

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  List<Annotation> annotations = [];

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: ArLocationWidget(
          annotations: annotations,
          showDebugInfoSensor: false,
          annotationWidth: 180,
          annotationHeight: 60,
          radarPosition: RadarPosition.bottomCenter,
          annotationViewBuilder: (context, annotation) {
            return AnnotationView(
              key: ValueKey(annotation.uid),
              annotation: annotation as Annotation,
            );
          },
          radarWidth: 160,
          scaleWithDistance: false,
          onLocationChange: (Position position) {
            Future.delayed(const Duration(seconds: 5), () {
              annotations = fakeAnnotation(position: position, numberMaxPoi: 10);
              setState(() {});
            });
          },
        ),
      ),
    );
  }
}

请注意，此示例中的fakeAnnotation函数需要你自己实现，用来生成模拟的数据集，或者你可以替换为从服务器获取的实际数据。

通过以上步骤，你就可以成功集成ar_location_view插件到你的Flutter项目中了。希望这些信息对你有所帮助！如果还有其他问题或需要进一步的帮助，请随时提问。