Async WMI Query in Inno Setup

Question

I'm trying to implement asynchronous WMI queries in my Inno Setup project. But I'm struggling with the event definitions. I'm getting a Type mismatcherror on the line

objSink.OnCompleted := @WMI_OnCompleted;

I am assuming that my event definition is wrong. How can I find the right object types for the event?

procedure QueryWMIAsync(Qry: string; var objSink: Variant);
var
  WbemLocator, WbemServices, WbemObjects: Variant;
begin
  log('WMI AsyncQuery: '+Qry);
  try
    WbemLocator := CreateOleObject('WbemScripting.SWbemLocator');
    objSink.OnCompleted := @WMI_OnCompleted; //<----- Error: Type mismatch
    objSink.OnObjectReady := @WMI_OnObjectReady;    

    WbemServices := WbemLocator.ConnectServer('localhost', 'root\CIMV2');
    WbemServices.ExecQueryAsync(objSink, Qry);    
  except
    MsgBox('ERROR on WMI Query <'+Qry+'>: '+GetExceptionMessage,mbError,MB_OK);
  end;
end;

procedure WMI_OnCompleted(hResult: HRESULT; error: Variant; asyncContext: Variant);
begin

end;

Answer 1

According to the Inno Setup Newsgroup this actually seems to be impossible. At least with my approach:

http://news.jrsoftware.org/read/article.php?id=30095&group=jrsoftware.innosetup.code#30095