Navigator.geolocation不更新打印稿屬性

Question

我在寫一個位置服務，它調用新的html5 navigator.geolocation類。但是，除非將「maximumAge」值更改爲「99999」，否則該服務將始終返回這些屬性的默認值，但我擔心它只能在短時間內運行。

這裏是我的locationService：

export class LocationService { 
private static _instance: LocationService = null; 
public Latitude: KnockoutObservable<number> = ko.observable(0); 
public Longitude: KnockoutObservable<number> = ko.observable(2); 

constructor() { 
    navigator.geolocation.getCurrentPosition((position) => { 
     this.Longitude(position.coords.longitude); 
     this.Latitude(position.coords.latitude); 
    },() => { 
     alert('please use HTML5 enabled browser'); 
      // TODO: use yahoo API and postcode from DB to get location long & lat fall back for browsers not supporting this call 
    }, { 
      timeout: 10000, 
      maximumAge: 1, 
      enableHighAccuracy: true 
     } 
    ); 
} 

public static GetInstance(): LocationService { 
    if (LocationService._instance === null) { 
     LocationService._instance = new LocationService(); 
    } 
    return LocationService._instance; 
} 

private noLocation() { 

} 

} 

這裏是我如何使用它在迪朗達爾部件：

import locationService = require("services/locationService"); 

export class testWidget{ 
public locationServ: locationService.LocationService = locationService.LocationService.GetInstance(); 
public Latitude: KnockoutObservable<number> = ko.observable(1); 
public Longitude: KnockoutObservable<number> = ko.observable(3); 

constructor() { 
    this.Latitude.subscribe(function (newLat) { 
     alert("test change : " + newLat); 
    }); 
    this.Latitude(this.locationServ.Latitude()); 
    this.Longitude(this.locationServ.Longitude()); 
} 

public activate() { 
    alert("test: " + this.Latitude() + this.Longitude()); 
} 



} 

return new testWidget(); 

此代碼提示 '測試的變化：0'，然後 '測試：02'除非我改變了超時時間，在這種情況下，它會提醒真正的長和長值。

任何和所有的幫助非常感謝，因爲我整天都把我的頭髮拉出來。提前致謝。

Answer 1

的成員被稱爲

public Latitude: KnockoutObservable<number> = ko.observable(1); 
public Longitude: KnockoutObservable<number> = ko.observable(3); 

之前構造體：

this.Latitude(this.locationServ.Latitude()); 
this.Longitude(this.locationServ.Longitude()); 

所以你有效地得到：

public Latitude: KnockoutObservable<number> = ko.observable(1); 
public Longitude: KnockoutObservable<number> = ko.observable(3); 
this.Latitude(this.locationServ.Latitude()); 
this.Longitude(this.locationServ.Longitude()); 

而且，由於locationServ有

public Latitude: KnockoutObservable<number> = ko.observable(0); 
public Longitude: KnockoutObservable<number> = ko.observable(2); 

0，2你得到0,2