如何在 EF 中计算 georaphy st_distance？

Question

我尝试使用 EF 中的 NpSql 计算地理距离，但返回的结果始终为几何。

       NetTopologySuite.Geometries.Coordinate coordinate1 = new NetTopologySuite.Geometries.Coordinate(12.25, 51.25);                       
            NetTopologySuite.Geometries.Point point1 = new NetTopologySuite.Geometries.Point(coordinate1);
            point1.SRID= 4326;
            

            NetTopologySuite.Geometries.Coordinate coordinate2 = new NetTopologySuite.Geometries.Coordinate(12.50, 51.25);
            NetTopologySuite.Geometries.Point point2 = new NetTopologySuite.Geometries.Point(coordinate2);
            point2.SRID = 4326;
            

            Console.WriteLine(point1.Distance(point2));

1. 创建坐标
2. 然后是新点
3. 设置SRID

Answer 1

最后，写了新课程并通过半正弦公式计算了地理距离

 public static class Distance
{

    
    /// <summary>
    /// Distance on a sphere: The Haversine Formula
    /// </summary>
    /// <returns>distance in meters</returns>
    public static double Haversine(Coordinate coordinateFirstPoint, Coordinate coordinateSecondPoint)
    {
        // Coordinate (longitude, latitude)

        double earthRadius = 6371008.7714;

        double temp = Math.Acos(Math.Sin(Math.PI * coordinateFirstPoint.Y / 180) * Math.Sin(Math.PI * coordinateSecondPoint.Y / 180) + 
            Math.Cos(Math.PI * coordinateFirstPoint.Y / 180) * Math.Cos(Math.PI * coordinateSecondPoint.Y / 180) * Math.Cos(Math.PI * coordinateFirstPoint.X / 180 - Math.PI * coordinateSecondPoint.X / 180));
        
        return temp*earthRadius;
    }
}