在dbgeography中如何返回距离km？

这是计算距离从当前位置到另一个列表中的距离的JSON结果，但我有一个问题，我无法将距离单位（度）转换为从dbgeography.location.distance到km的问题这是我的代码：在dbgeography中如何返回距离km？

string CurrentLocation = String.Format("POINT(" + CurrentLat + " " + CurrentLng + ")", 4326); 
       DbGeography point = DbGeography.PointFromText(CurrentLocation, DbGeography.DefaultCoordinateSystemId); 

       var places = (from u in context.schoolinfo 

           orderby u.Location.Distance(point.Buffer(dist)) 

           select u).Take(10).Select(x => new schoollinfo() { Name = x.name, Lat = x.Location.Latitude, Lng = x.Location.Longitude, Distance = x.Location.Distance(point.Buffer(dist)) }); ; 

       var nearschools = places.ToList(); 
       return Json(nearschools, JsonRequestBehavior.AllowGet);

Print screen of result

来源

2017-10-21 oussama_tr

是否https://earthscience.stackexchange.com /曲estions/7350/convert-grid-resolution-from-degrees-to-kilocity或https://stackoverflow.com/questions/13934169/system-data-spatial-dbgeography-distance-units help？ – mjwills

@mjwills第一个链接它interessant，但它仍然很难.. –

为calaculate远处看的角度（经纬度）不点（经纬度），这样的代码会因为这改变：

 select u).Take(10).Select(x => new schoollinfo() { Name = x.name, Lat = x.Location.Latitude, Lng = x.Location.Longitude, Distance = DbGeography.FromText("POINT(" + x.Location.Longitude + " " + x.Location.Latitude + ")", 4326).Distance(point) });

来源

2017-10-22 18:09:55

在dbgeography中如何返回距离km？

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