Flutter活动识别插件flutter_activity_recognition的使用

Features

• 可以请求活动识别权限。
• 可以订阅ActivityStream以实时监听活动。

Getting started

添加依赖

为了使用此插件，需在pubspec.yaml文件中添加flutter_activity_recognition作为依赖。例如：

dependencies:
  flutter_activity_recognition: ^4.0.0

配置平台特定权限

Android配置

打开AndroidManifest.xml文件，并在<manifest>和<application>标签之间添加以下权限：

<uses-permission android:name="android.permission.ACTIVITY_RECOGNITION" />
<uses-permission android:name="com.google.android.gms.permission.ACTIVITY_RECOGNITION" />

iOS配置

打开ios/Runner/Info.plist文件，并在<dict>标签内添加以下权限：

<key>NSMotionUsageDescription</key>
<string>Used to recognize user activity information.</string>

How to use

检查并请求权限

检查用户是否授予了活动识别权限，如果未授予，则请求权限。

Future<bool> _checkAndRequestPermission() async {
  ActivityPermission permission =
      await FlutterActivityRecognition.instance.checkPermission();
  if (permission == ActivityPermission.PERMANENTLY_DENIED) {
    // 权限已被永久拒绝
    return false;
  } else if (permission == ActivityPermission.DENIED) {
    permission =
        await FlutterActivityRecognition.instance.requestPermission();
    if (permission != ActivityPermission.GRANTED) {
      // 权限被拒绝
      return false;
    }
  }

  return true;
}

实时监听活动

使用activityStream属性来实时监听活动。

StreamSubscription<Activity>? _activitySubscription;

Future<void> _subscribeActivityStream() async {
  if (await _checkAndRequestPermission()) {
    _activitySubscription = FlutterActivityRecognition.instance.activityStream
        .handleError(_onError)
        .listen(_onActivity);
  }
}

void _onActivity(Activity activity) {
  print('activity detected >> ${activity.toJson()}');
}

void _onError(dynamic error) {
  print('error >> $error');
}

示例Demo

这是一个完整的示例代码，演示了如何使用flutter_activity_recognition插件来监听用户的活动。

import 'dart:async';
import 'dart:developer' as dev;

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_activity_recognition/flutter_activity_recognition.dart';

void main() => runApp(ExampleApp());

class ExampleApp extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => _ExampleAppState();
}

class _ExampleAppState extends State<ExampleApp> {
  final ValueNotifier<ActivityResult?> _activityResult = ValueNotifier(null);

  StreamSubscription<Activity>? _activitySubscription;

  Future<void> _requestPermission() async {
    ActivityPermission permission =
        await FlutterActivityRecognition.instance.checkPermission();
    if (permission == ActivityPermission.PERMANENTLY_DENIED) {
      throw Exception('permission has been permanently denied.');
    } else if (permission == ActivityPermission.DENIED) {
      permission =
          await FlutterActivityRecognition.instance.requestPermission();
      if (permission != ActivityPermission.GRANTED) {
        throw Exception('permission is ${permission.name}.');
      }
    }
  }

  void _startService() async {
    try {
      await _requestPermission();

      // 订阅活动流
      _activitySubscription = FlutterActivityRecognition.instance.activityStream
          .handleError(_onError)
          .listen(_onActivity);
    } catch (error) {
      _onError(error);
    }
  }

  void _onActivity(Activity activity) {
    dev.log('activity detected >> ${activity.toJson()}');
    _activityResult.value = ActivityResult.success(activity);
  }

  void _onError(dynamic error) {
    String errorMessage;
    if (error is PlatformException) {
      errorMessage = error.message ?? error.code;
    } else {
      errorMessage = error.toString();
    }

    dev.log('error >> $errorMessage');
    _activityResult.value = ActivityResult.error(errorMessage);
  }

  @override
  void initState() {
    super.initState();
    _startService();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Flutter Activity Recognition'),
          centerTitle: true,
        ),
        body: _buildContentView(),
      ),
    );
  }

  Widget _buildContentView() {
    return ValueListenableBuilder(
      valueListenable: _activityResult,
      builder: (context, result, _) {
        return ListView(
          physics: const BouncingScrollPhysics(),
          padding: const EdgeInsets.all(8.0),
          children: _buildListViewItems(result),
        );
      },
    );
  }

  List<Widget> _buildListViewItems(ActivityResult? result) {
    if (result == null) {
      return [
        Text('waiting for activity..'),
      ];
    }

    final String? error = result.error;
    if (error != null) {
      return [
        Text('time: ${DateTime.now()}'),
        Text('error: $error'),
      ];
    }

    return [
      Text('time: ${DateTime.now()}'),
      Text('type: ${result.data?.type}'),
      Text('confidence: ${result.data?.confidence}'),
    ];
  }

  @override
  void dispose() {
    _activitySubscription?.cancel();
    _activityResult.dispose();
    super.dispose();
  }
}

class ActivityResult {
  ActivityResult._private({this.data, this.error});

  final Activity? data;
  final String? error;

  factory ActivityResult.success(Activity data) =>
      ActivityResult._private(data: data);

  factory ActivityResult.error(String error) =>
      ActivityResult._private(error: error);
}

Background Mode

如果您希望在后台使用此插件，请使用flutter_foreground_task插件。

More Documentation

• 了解由该插件提供的models
• 迁移至新版本

Support

如果您在使用插件时遇到任何bug或问题，请在GitHub上注册问题。您也可以通过邮箱联系我们：hwj930513@naver.com。