如何返回以米為單位的地理距離？

Question

在這個例子中，我需要限制搜索來搜索僅僅在10000米左右的地方，這種方法對我來說是行不通的。 這是我的代碼：

  using (GeolocationTestEntities context = new GeolocationTestEntities ())
        {


            var distance = 10000;
            var distanceInMeters = distance * 0.6214;

            var CurrentLocation = DbGeography.FromText("POINT(" + CurrentLat + " " + CurrentLng + ")");
                var places = (from u in context.schoolinfo
                              where u.Location.Distance(CurrentLocation) < distanceInMeters
                              select u).Take(10).Select(x => new schoollinfo() { Name = x.name, Lat = x.Location.Latitude, Lng = x.Location.Longitude, Distance = x.Location.Distance(CurrentLocation) });
                var nearschools = places.ToList();
                HttpCookie cookie = new HttpCookie("Cookie");
                cookie["CurrentLat"] = CurrentLat;
                cookie["CurrentLng"] = CurrentLng;
                this.ControllerContext.HttpContext.Response.Cookies.Add(cookie);

                return Json(nearschools, JsonRequestBehavior.AllowGet);


        }

謝謝，

Answer 1

您不應該使用（距離* 0.6214）。 因為Distance（）方法已經使用了米。