Question

我正在编写一个调用新的html5 navigator.geolocation类的位置服务。但是，除非我更改了＆＃39; maximumAge＆＃39;否则服务始终会返回这些属性的默认值。价值为＆＃39; 99999＆＃39;但后来我担心它只会在很短的时间内起作用。

这是我的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() {

}

}

这是我如何在durandal小部件中使用它：

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();

此代码提醒＆＃39;测试更改：0＆＃39;然后＆＃39;测试：02＆＃39;除非我改变超时，否则它会提醒实际的长和纬度值。

我非常感谢所有人的帮助，因为我整天都把头发拉了过来。提前谢谢。

Answer 1

会员被称为

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

在构造函数体之前

：

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

所以你有效地拥有：

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

因为locationServ有

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

0，2你得到0.2

Navigator.geolocation不更新typescript属性

1 个答案: