从SQL Server 2008到C#的Geo函数(多边形/地图区域内外的纬度和经度点)
在SQL Server 2008中,我有:
Declare @pointIn geometry Declare @pointOut geometry Declare @polygon geometry SET @polygon = geometry::STGeomFromText('POLYGON((40 -9,40 -6,35 -6,35 -9,40 -9))', 4326) SET @pointIn = geometry::STGeomFromText('POINT (39 -8)', 4326) SET @pointOut = geometry::STGeomFromText('POINT (41 -3)', 4326) select @polygon.STIntersects(@pointIn) select @polygon.STIntersects(@pointOut)
正如预期的那样,我得到了结果1
和0
。
现在我尝试使用库将相同的代码带到C#: Microsoft.SqlServer.Types.dll
使用以下代码:
var p1lat = 40; var p1long = -9; var p2lat = 40; var p2ong = -6; var p3lat = 35; var p3ong = -6; var p4lat = 35; var p4ong = -9; var pILat = 39; var pILong = -8; var pOLat = 41; var pOLong = -3; System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("en-US"); const string polygonFormat = "POLYGON(({0} {1},{2} {3},{4} {5},{6} {7},{0} {1}))"; var polygon = string.Format(polygonFormat, p1lat, p1long, p2lat, p2ong, p3lat, p3ong, p4lat, p4ong); var geometryString = new SqlChars(new SqlString(polygon)); var area = SqlGeography.STPolyFromText(geometryString, 4326); var pointIn = SqlGeography.Point(pILat, pILong, 4326); var pointOut = SqlGeography.Point(pOLat, pOLong, 4326); Console.WriteLine(area.STIntersects(pointIn)); Console.WriteLine(area.STIntersects(pointOut));
我总是得到False
, False
……它应该是True
, False
有人可以帮忙吗?
谢谢
SqlGeography.Point
和SqlGeography.STPointFromText
使用不同的坐标顺序。 请尝试以下解决方案之一来解决此问题:
- 在
SqlGeography.Point
方法调用中交换坐标; - 使用WKT语法(
SqlGeography.STPointFromText
)创建点。