ShrlAlgoToolkit/ShrlAlgoToolkit.RevitCore/Extensions/ReferenceExtensions.cs

using Autodesk.Revit.DB;

namespace ShrlAlgoToolkit.RevitCore.Extensions
{
    public static class ReferenceExtensions
    {
        public static Curve GetActualEdgeCurve(this Reference selectedEdge, Document doc)
        {
            var stable = selectedEdge.ConvertToStableRepresentation(doc);
            bool SolidInstance = stable.Contains("INSTANCE");//如果是Instance的话，获取到的是族类型的边
            Element elem = doc.GetElement(selectedEdge.ElementId);
            var selEdge = elem.GetGeometryObjectFromReference(selectedEdge) as Edge;
            var selEdgeCurve = selEdge.AsCurve();
            if (SolidInstance)
            {
                Transform tf = Transform.Identity;
                if (elem is FamilyInstance instance)
                {
                    tf = instance.GetTransform();
                }
                return selEdgeCurve.CreateTransformed(tf);
            }
            return selEdgeCurve;
        }
    }
}