Set Elevation Points on a Feature Line (API)

Sometimes the Civil 3D API can be a bit confusing. Sometimes the API does a similar task in one place and a totally different way in another place. Setting elevation point(s) on a feature line is one such case. It can be a bit confusing on trying to figure out what exactly is required. Below is some sample code that shows how to set elevation points, assuming you already have a feature line created.

        Dim dPointPL(8) As Double
        dPointPL(0) = 2010: dPointPL(1) = 2010
        dPointPL(3) = 2579: dPointPL(4) = 2579
        dPointPL(6) = 3010: dPointPL(7) = 2510
    
    ' SetPointElevation Method sets the elevation by input point.
        Dim dPointElev(2) As Double
        dPointElev(0) = 2010: dPointElev(1) = 2010: dPointElev(2) = 43
        oFeatureLine2.SetPointElevation dPointElev
        
    ' SetPointsElevation Method sets the elevation by input points.
        Dim vPointsPL As Variant
        vPointsPL = dPointPL
        vPointsPL(2) = 67
        vPointsPL(5) = 79
        vPointsPL(8) = 109
        oFeatureLine2.SetPointsElevation vPointsPL

If I remember correctly you need to make sure the point is on the feature line before setting the point elevation.