How to project a point with ProjectEx

This sample shows how to project a point using the ProjectEx method on IGeometry2. If the input and output spatial references use different geographic coordinate systems, a geographic (datum) transformation must be defined. The Project method on IGeometry does not support geographic transformations.

How to use

Add the code to your project.
Modify with your coordinate systems, geometries, and transformation.

[VBA]


        Private Sub using_projectex()
    Dim pPoint As IPoint
    Set pPoint = New Point
    
    Dim dLonDecimalDegrees As Double
    Dim dLatDecimalDegrees As Double
    
    dLonDecimalDegrees = -100#
    dLatDecimalDegrees = 40#
    
    Dim pGeoCoordSystem As ISpatialReference
    Dim pProjCoordSystem As ISpatialReference
    Dim pGeoTrans As IGeoTransformation
    Dim pSpatRefFact As ISpatialReferenceFactory
    
    Set pSpatRefFact = New SpatialReferenceEnvironment
    Set pGeoCoordSystem = pSpatRefFact.CreateGeographicCoordinateSystem(esriSRGeoCS_NAD1927)
    Set pPoint.SpatialReference = pGeoCoordSystem
    pPoint.PutCoords dLonDecimalDegrees, dLatDecimalDegrees
    
    ' Create the output coordinate system.
    Set pProjCoordSystem = pSpatRefFact.CreateProjectedCoordinateSystem(esriSRProjCS_NAD1983UTM_13N)
    
    ' Create a geographic transformation between the input and output
    ' geographic coordinate systems are different.
    Set pGeoTrans = pSpatRefFact.creategeotransformation(esriSRGeoTransformation_NAD_1927_TO_NAD_1983_NADCON)
    
    ' Create a geometry object and project it.
    Dim pGeo As IGeometry2
    Set pGeo = pPoint
    Set pGeo.SpatialReference = pGeoCoordSystem
    pGeo.ProjectEx pProjCoordSystem, esriTransformForward, pGeoTrans, 0, 0, 0
End Sub