Question

我正在开发一个应用程序，它显示从用户当前位置到某个点的行驶距离。有几千个坐标点，应用程序需要非常快速地计算距离。以下是我正在使用的方法。

public async Task<int> findRouteLength(System.Device.Location.GeoCoordinate currentPosition, System.Device.Location.GeoCoordinate businessPosition)
    {


        List<System.Device.Location.GeoCoordinate> routePositions = new List<System.Device.Location.GeoCoordinate>();
        routePositions.Add(currentPosition);
        routePositions.Add(businessPosition);
        RouteQuery query = new RouteQuery();
        query.TravelMode = TravelMode.Driving;
        query.Waypoints = routePositions;
        Route route = await query.GetRouteAsync();
        return route.LengthInMeters;

    }

但是，此任务一秒钟内只能计算不超过5-6个距离。有没有更快的方法来计算Windows Phone 8 c＃中的行驶距离？

Answer 1

试试这个，它应该快得多

public double CalculateDistance(System.Device.Location.GeoCoordinate geo, System.Device.Location.GeoCoordinate geo2)
{
    //var R = 6371; // result in km
    var R = 6371000; // result in m
    var dLat = (geo2.Latitude - geo.Latitude).ToRad();
    var dLon = (geo2.Longitude - geo.Longitude).ToRad();
    var lat1 = geo.Latitude.ToRad();
    var lat2 = geo2.Latitude.ToRad();

    var a = Math.Sin(dLat / 2) * Math.Sin(dLat / 2) +
            Math.Sin(dLon / 2) * Math.Sin(dLon / 2) * Math.Cos(lat1) * Math.Cos(lat2);
    var c = 2 * Math.Atan2(Math.Sqrt(a), Math.Sqrt(1 - a));
    return R * c;
}

ToRad扩展程序

static class Ext
{
    public static double ToRad(this double val)
    {
        return (Math.PI / 180) * val;
    }
}

在wp8 c＃中计算行驶距离的最快方法是什么？

1 个答案: