coordinate system - Determining if spatial reference Geographic or Projected using ArcObjects?

I have the user select a coordinate system with the Spatial Reference Dialog.

Is there a simple way to determine if the resulting spatial reference is a Projected or Geographic CS?

I would have thought that this would be an attribute of the spatialReference, but it does not seem to be.

Answer

You can check the object type like so:

ISpatialReference ref = ...; // This is your spatial reference
if (ref is IGeographicCoordinateSystem) {

    //Geographic
} else if (ref is IProjectedCoordinateSystem) {
    // Projected
} else {
    // Unknown coordinate system
}