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react-native - React Native Expo：使用任务管理器在后台获取地理位置

问题描述

我一直在开发一个反应本机应用程序，我必须以 10 秒的间隔获取地理位置并将其更新到服务器。当模拟器处于活动状态/在前台时，我能够做同样的事情。

但是，当应用程序最小化时，它不起作用。我尝试使用 expo 任务管理器，但该功能在后台运行时似乎没有运行。

这里有什么错误？我附上了我的代码和输出。

我正在使用模拟器和个人设备使用 android 11。

这是我的代码：


import * as Permissions from 'expo-permissions';
import * as Location from 'expo-location';
import * as TaskManager from 'expo-task-manager';

//Navigator
import Navigator from './routing/Routing';

const Main = () => {
  const [gpsLatitude, setgpsLatitude] = useState(null);
  const [gpsLongitude, setgpsLongitude] = useState(null);
  const [batteryLevel, setBatteryLevel] = useState(null);

  useEffect(() => {
    (async () => await _askForLocationPermission())();

    const interval = setInterval(() => {
      uploadDataAtInterval();
    }, 10000);
    return () => clearInterval(interval);
  });

  const backgroundLocationFetch = async () => {
    const { status } = await Location.requestPermissionsAsync();
    if (status === 'granted') {
      console.log('cmon dance with me!')
      await Location.startLocationUpdatesAsync('FetchLocationInBackground', {
        accuracy: Location.Accuracy.Balanced,
        timeInterval: 10000,
        distanceInterval: 1,
        foregroundService: {
          notificationTitle: 'Live Tracker',
          notificationBody: 'Live Tracker is on.'
        }
      });
    }
  }


  const _askForLocationPermission = async () => {
    (async () => {
      let { status } = await Location.requestPermissionsAsync();
      if (status !== 'granted') {
        setgpsErrorMsg('Permission to access location was denied');
      }
    })();
  };

  const uploadDataAtInterval = async () => {
      console.log('upload using axios');
      
  }

  const getGPSPosition = async () => {
    let location = await Location.getCurrentPositionAsync({accuracy:Location.Accuracy.High});
    setgpsLatitude(location.coords.latitude);
    setgpsLongitude(location.coords.longitude);
  }


  backgroundLocationFetch();

  return(
    <Navigator />
  )
};

TaskManager.defineTask('FetchLocationInBackground', ({ data, error }) => {
  if (error) {
    console.log("Error bg", error)
    return;
  }
  if (data) {
    const { locations } = data;
    console.log("BGGGG->", locations[0].coords.latitude, locations[0].coords.longitude);
  }
});

export default Main;

输出：

BGGGG 12.88375 80.08169
BGGGG 12.88375 80.08169
App: Not logged on now false  //at every 10secs
App: Not logged on now false
App: Not logged on now false
App: Not logged on now false
App: Not logged on now false
App: Not logged on now false

标签： react-nativeexporeact-native-android

解决方案

对于稍后查看此内容的任何人，请确保您在物理设备上测试您的应用程序。模拟器并不真正支持任务管理器和后台获取正确！

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