ArcEngine下投影坐标和经纬度坐标的相互转换

投影转经纬度

private
IPoint PRJtoGCS(
double
x,
double
y)
{
   
IPoint pPoint =
new
PointClass();
   
pPoint.PutCoords(x, y);
   
ISpatialReferenceFactory pSRF =
new
SpatialReferenceEnvironmentClass();
   
pPoint.SpatialReference = pSRF.CreateProjectedCoordinateSystem(
2414
);
pPoint.Project(pSRF.CreateGeographicCoordinateSystem((
int
)esriSRGeoCSType.esriSRGeoCS_Beijing1954));
   

return
pPoint;
}

其中，pPoint.SpatialReference =
pSRF.CreateProjectedCoordinateSystem(
2414
);

这行代码是设置pPoint
的空间参考，也就是要转化的点的投影坐标。如果不知道投影坐标的话，转化会报异常。

2414
为该投影的enum
值

pPoint.Project(pSRF.CreateGeographicCoordinateSystem((
int
)esriSRGeoCSType.esriSRGeoCS_Beijing1954));

将该点的投影坐标转化为经纬度。

经纬度到投影：

private
IPoint GCStoPRJ(IPoint pPoint,
int
GCSType,
int
PRJType)
{
   
ISpatialReferenceFactory pSRF =
new
SpatialReferenceEnvironmentClass();
   
pPoint.SpatialReference =
pSRF.CreateGeographicCoordinateSystem(GCSType);
   

pPoint.Project(pSRF.CreateProjectedCoordinateSystem(PRJType));
   

return
pPoint;
}

转载自：https://blog.csdn.net/jianzhanger/article/details/6322177