[CONNECT .NET] Get In-Memory Element from COM Impossible

Question

I want to get a .NET Element from a COM Element ... 
 using Bentley.DgnPlatformNET;
using Bentley.DgnPlatformNET.Elements;
using Bentley.MstnPlatformNET;
using BCOM = Bentley.Interop.MicroStationDGN;
 
 Element GetElementFromComElement (BCOM.Element oElement, bool addToModel)
{
 if (addToModel)
 {
 BCOM.Application app = Bentley.MstnPlatformNET.InteropServices.Utilities.ComApp;
 app.ActiveModelReference.AddElement(oElement);
 }
 IntPtr pointer = (IntPtr)oElement.MdlElementRef();
 Element el = Element.GetFromElementRef(pointer);
 return el;
} 
 If I call the above function with addToModel True, it works. If I call the function with addToModel False, it returns a null. But I don't want to write the COM element to file: I want an in-memory .NET Element . What's going on? 
 I've marked this thread as solved, because a work-around exists. The question: 'Can we obtain a .NET Element from COM?' remains unanswered.

Jon Summers · Accepted Answer

Jan Šlegr said: I agree it's the issue not solved by Bentley 
 The InterOp route suggested by Yongan.Fu in his csAddIn project works well. I've attached some code that implements both a normal cell placement tool and a shared cell placement tool. Both call VBA COM classes and methods. 
 To my pleasant surprise, it's possible, in a C# implementation, for a class to inherit from a COM interface ( IPrimitiveCommandEvents )... 
 class PlaceSharedCellComTool : IPrimitiveCommandEvents
 {
 } 
 That gives us the state engine provided by COM, which works just as it does in VBA. 
 PlaceCellExample.zip

[CONNECT .NET] Get In-Memory Element from COM Impossible

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