• Create a prg file for the interface
  

begin namespace COMTest

using System.Runtime.InteropServices

[ComVisible(true)];
[Guid("750E557E-9DA6-4508-A36E-C4141D27B5D4")];
[InterfaceType(ComInterfaceType.InterfaceIsIDispatch)];
interface ICOMTester
	
[DispId(1)];
method Output() as string
	
end interface          

end namespace

The GUID needs to be created with the GuidGen.exe tool.

• Create a prg file for the functionality itself:
  

using System.Runtime.InteropServices

begin namespace COMTest

[ComVisible(true)];
[Guid("7D1DF22E-3A3D-431C-8BEE-A2F40C53A249")];
[ClassInterface(ClassInterfaceType.None)];
[ProgId("COMTest.COMTester")];
class COMTester implements ICOMTester
	
public constructor()
	
	return
	
public virtual method Output() as string
	
	return "Hi from my component"
	
end class	

end namespace

• Build the application (i.e. the DLL)
  
• create a snk file: sn - k COMTest.snk
  
• add this snk file as signature to your DLL (Application Properties - Advanced - Assembly signing in XIDE)
  
• build your application
  
• read the public key from the application: sn -T COMTest.dll (upper case “T”) and write it somewhere
  
• create the TLB with administrative (elevated) rights: tlbexp COMTest.dll
• create the automation server in VO using the created TLB
• edit the Init() method of the created VO class adding the cProgId and the cClsId using the GUIDs from your library. The cClsId uses the GUID from your class, the cIID the one from your interface.

METHOD Init(ObjID, fROTCHECK) CLASS ICOMTester

self:cProgID := "COMTest.COMTester"
self:cClsID := "{7D1DF22E-3A3D-431C-8BEE-A2F40C53A249}" 
self:cIID := "{750E557E-9DA6-4508-A36E-C4141D27B5D4}"
SUPER:Init(ObjID, 0, .T., fRotCheck)
SELF:_dwFuncs := 1
SELF:_dwVars := 0

RETURN SELF

• create the manifest for your COM assembly: mt.exe -managedassemblyname:COMTest.dll -nodependency -out:COMTest.dll.manifest
• fix this manifest by replacing processorarchitecture “msil” by “win32” (and maybe beautify the file…)
• move this manifest in the resources subfolder of your application directory (XIDE)
• create there a file “Manifest.CREATEPROCESS_MANIFEST_RESOURCE_ID.rc” with the content

CREATEPROCESS_MANIFEST_RESOURCE_ID RC_RT_MANIFEST "COMTest.dll.manifest"

• add this file to XIDE with Add Existing - Add Native Resources
• build your DLL and check with a manifest viewer if your binary contains that manifest
• hopefully your VO application has a manifest. Add a reference to your COM dll:

  <dependency>
  	<dependentAssembly>
  		<assemblyIdentity
  			type="win32"
  			name="COMTest"
  			version="1.0.0.0"
  			publicKeyToken="ff428fdf619029ef"
  			>
  		</assemblyIdentity>
  	</dependentAssembly>
  </dependency>

using the public key token you created with “sn -T”. Pleasy pay attention that the version information must be exactly the same between your manifests and the COM DLL!

Possible problems:

• you can encounter error 0x80131044 when trying to create the TLB from a already strong named DLL if the dependencies of your COM dll are not strong named. In this case simply compile your library without the signing option
• you should set the namespace also in the project properties
• the exported class cannot have the same name as the COM DLL itself
• to debug your VO application:

sxstrace Trace -logfile:systrace.out
sxstrace Parse -logfile:systrace.out -outfile:sxstrace.txt
notepad sxstrace.txt