DotNETWinFormsOleControl

A minimalistic example of a .NET8-based WinForms custom control, that can also be used as an OLE Control in Visual Basic for Applications.

Demonstrates how to scaffold everything, so that it works.

Prerequisites

Visual Studio 2022 with C++ Build tools (MSVC v143) installed.

Open the solution in Visual Studio.
Build the TypeLib project. In the ./tlb folder it will produce a .TLB-file, which is needed by the Control project.
Build the Control project. In its /bin/Debug/net8.0-windows folder it will produce the custom control's DLL (Control.dll) and also a custom COM activation host library, aka "shim" (Control.comhost.dll). At this point you should be able to open that Control.comhost.dll file with OleView32 and see the typelib injected into it.
Register the shim file: regsvr32 Control.comhost.dll. You will need an elevated command prompt for that.
Open VBA editor in Word or Excel and create an empty form. You should now see the DotNETWinFormsCustomControlLib.DotNETWinFormsCustomControl control in the list of "additional controls":
Add the DotNETWinFormsCustomControlLib.DotNETWinFormsCustomControl control onto the form and observe the control working: