int Id {get; set;} 

Id:int 

// create Cimatron App Access object
interop.CimAppAccess.AppAccess aAppAccess = new interop.CimAppAccess.AppAccess();
//Get application object from App access
interop.CimatronE.IApplication CimApp = (interop.CimatronE.IApplication)aAppAccess.GetApplication();
// Get active document from application
interop.CimBaseAPI.ICimDocument aDOC = (interop.CimBaseAPI.ICimDocument)CimApp.GetActiveDoc();
if (aDOC != null) // Check if document was found
{
interop.CimMdlrAPI.IModelContainer aModelCont = (interop.CimMdlrAPI.IModelContainer)aDOC;
// Create the Sketcher procedure depended on the type of the active document. For now we take part document
if (aDOC.Type == interop.CimBaseAPI.DocumentEnumType.cmPart)
{
// If active document is part then get the MdlrModel from model container
interop.CimMdlrAPI.MdlrModel aMdlrModel = (interop.CimMdlrAPI.MdlrModel)aModelCont.Model;
//Create sketcher procedure on Modeler Model
interop.CimMdlrAPI.MdSketcher aMdSketcherProcedure =
(interop.CimMdlrAPI.MdSketcher)aMdlrModel.CreateProcedure(interop.CimMdlrAPI.MdProcedureType.cmSketcherProcedure);
// Cast MdSketcher to IMdSketcher to get sketcher object
interop.CimMdlrAPI.IMdSketcher aIMdSketcher = (interop.CimMdlrAPI.IMdSketcher)aMdSketcherProcedure;
interop.CimServicesAPI.ISketcher aISketcher = (interop.CimServicesAPI.ISketcher)aIMdSketcher.Sketcher;
//Create SkPoint type object
interop.CimServicesAPI.ISkObject aSkPointObj= aISketcher.CreateObject(interop.CimServicesAPI.SketchObjectType.cmSketchPoint);
interop.CimServicesAPI.ISkPoint aSkPoint = (interop.CimServicesAPI.ISkPoint)aSkPointObj;
//while adding object to sketcher it will set new SkId for object
int aId =aISketcher.AddObject(aSkPointObj);

//get the SkId for object
int aSkId= aSkPointObj.Id;
// aId and aSkId are same,if we do not set value to aSkPointObj.Id .
}
}  

import clr
#Adding references of required interop dlls
clr.AddReference("interop.CimAppAccess")
clr.AddReference("interop.CimatronE")
clr.AddReference("interop.CimServicesAPI")
clr.AddReference("interop.CimBaseAPI")
clr.AddReference("interop.CimMdlrAPI")

#importing modules from interop dlls
import interop.CimAppAccess
import interop.CimatronE
import interop.CimServicesAPI
import interop.CimBaseAPI
import interop.CimMdlrAPI

#Getting AppAccess Object
aCimAppAccess = interop.CimAppAccess.AppAccess()
#Getting instance of CimatronE Application
aCimApp = None
while (aCimApp == None) :
aCimApp = (interop.CimatronE.IApplication)(aCimAppAccess.GetApplication())
aDocument = (interop.CimatronE.ICimDocument)(aCimApp.GetActiveDoc())
if (aDocument != None) :
if (aDocument.Type == interop.CimatronE.DocumentEnumType.cmPart) :
aModelCont = (interop.CimMdlrAPI.IModelContainer)(aDocument)
#If active document is part then get the MdlrModel from model container
aMdlrModel = (interop.CimMdlrAPI.MdlrModel)(aModelCont.Model)
aMdSketcherProcedure = (interop.CimMdlrAPI.MdSketcher)(aMdlrModel.CreateProcedure(interop.CimMdlrAPI.MdProcedureType.cmSketcherProcedure))
# Cast MdSketcher to IMdSketcher to get sketcher object
aIMdSketcher = (interop.CimMdlrAPI.IMdSketcher)(aMdSketcherProcedure)
aISketcher = (interop.CimServicesAPI.ISketcher)(aIMdSketcher.Sketcher)
#Create SkPoint type object
aSkPointObj= (interop.CimServicesAPI.ISkObject)(aISketcher.CreateObject(interop.CimServicesAPI.SketchObjectType.cmSketchPoint))
aSkPoint = (interop.CimServicesAPI.ISkPoint)(aSkPointObj)
#get the SkId for object
aSkId= aSkPointObj.get_Id()