获取ionic2中的当前位置

Question

我是Ionic 2的新手并且遵循一些教程.

在这种情况下,我需要更改以下方法:

 applyHaversine(locations){

        let usersLocation = {


            lat: 40.713744, 
            lng: -74.009056
        };

        locations.map((location) => {

            let placeLocation = {
                lat: location.latitude,
                lng: location.longitude
            };

            location.distance = this.getDistanceBetweenPoints(
                usersLocation,
                placeLocation,
                'miles'
            ).toFixed(2);
        });

        return locations;
    }

您可以看到变量usersLocation是硬编码的:

let usersLocation = {


            lat: 40.713744, 
            lng: -74.009056
        };

我想到达真正的用户位置.

我见过Geolocation.getCurrentPosition()方法,但在这种情况下我不知道如何实现它.

谢谢

EDITED

 applyHaversine(locations){
        Geolocation.getCurrentPosition().then((resp) => {

        let  latitud = resp.coords.latitude
        let longitud = resp.coords.longitude
        }).catch((error) => {
          console.log('Error getting location', error);
        });

  console.log(this.latitud);
        let usersLocation = {

           lat:  this.latitud, 
           lng:  this.longitud 
        };

Answer 1

我会使用Geolocation cordova插件.你可以用它来访问它ionic-native.首先,您需要安装插件:

$ ionic plugin add cordova-plugin-geolocation --save

然后你可以像这样使用它:

import { Geolocation } from 'ionic-native';

Geolocation.getCurrentPosition().then(res => {
  // res.coords.latitude
  // res.coords.longitude
}).catch((error) => {
  console.log('Error getting location', error);
});

https://ionicframework.com/docs/v2/native/geolocation/

编辑:

您的更新代码几乎是正确的.您在代码中犯了2个小错误:

1. 您定义了2个局部变量(let latitud和let longitud),但稍后在代码中使用this.latitud和访问它们this.longitud.this始终引用您的类中定义的变量,因此这些变量将是未定义的.您必须使用局部变量或类范围变量,但这取决于您的体系结构.两者都有效.

2. Geolocation.getCurrentPosition()返回一个承诺.这意味着内部代码.then(() => {})将在稍后执行(只要插件具有您的位置的结果).但是你的代码的其余部分不在其中then,这意味着它将在你拥有该位置之前执行.因此,您需要将整个代码复制到then以下内容中:

   applyHaversine(locations) {
     Geolocation.getCurrentPosition().then(res => {
       let usersLocation = {
         lat: res.coords.latitude, 
         lng: res.coords.longitude
       };
   
       locations.map((location) => {
   
         let placeLocation = {
           lat: location.latitude,
           lng: location.longitude
         };
   
         location.distance = this.getDistanceBetweenPoints(
           usersLocation,
           placeLocation,
           'miles'
         ).toFixed(2);
       });
   
     console.log(locations); // This will now have your updated distances
   
     }).catch((error) => {
       console.log('Error getting location', error);
     });
   
     return locations; // this will not work because the code above is asynchronous
   }
   

编辑2:

一个工作的例子是:

applyHaversine(locations) {
  return new Promise((resolve, reject) => {
    Geolocation.getCurrentPosition().then(res => {
      let usersLocation = {
        lat: res.coords.latitude, 
        lng: res.coords.longitude
      };

      locations.map((location) => {

        let placeLocation = {
          lat: location.latitude,
          lng: location.longitude
        };

        location.distance = this.getDistanceBetweenPoints(
          usersLocation,
          placeLocation,
          'miles'
        ).toFixed(2);
      });

    resolve(locations); // As soon as this is called, the "then" in will be executed in the function below.

    }).catch(reject);
  });
}

你在哪里使用这个功能:

doSomething(locations) {
  this.applyHaversine(locations).then(res => {
    // The logic after you have your new results goes here.
    console.log(res); // res will be the value that you passed into the resolve function above, in this case your updated locations array
  }
}