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
};
我会使用Geolocation cordova插件.您可以使用ionic-native访问它.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：
>您定义了2个局部变量(让latitud和let),但是稍后在代码中使用this.latitud和this.longitud来访问它们.这总是指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.
> Geolocation.getCurrentPosition()返回一个promise.这意味着.then(()=> {})中的代码将在稍后执行(只要插件具有您的位置的结果).但是你的代码的其余部分都在那个代码之外,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,'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,'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
}
}
