private static System.Collections.Generic.IEnumerable <System.Guid> getGUIDs(string className) { uint requiredSize; var guidArray = new System.Guid[256]; if (SetupDiClassGuidsFromName(className, ref guidArray[0], (uint)guidArray.Count(), out requiredSize)) { while (requiredSize > 0) { yield return(guidArray[--requiredSize]); } } }