Navigator.geolocation不更新打印稿属性

Question

我在写一个位置服务，它调用新的html5 navigator.geolocation类。但是，除非将“maximumAge”值更改为“99999”，否则该服务将始终返回这些属性的默认值，但我担心它只能在短时间内运行。

这里是我的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() { 

} 

} 

这里是我如何使用它在迪朗达尔部件：

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(); 

此代码提示 '测试的变化：0'，然后 '测试：02'除非我改变了超时时间，在这种情况下，它会提醒真正的长和长值。

任何和所有的帮助非常感谢，因为我整天都把我的头发拉出来。提前致谢。

Answer 1

的成员被称为

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

之前构造体：

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，由于locationServ有

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

0，2你得到0,2