How do I translate a C union into Delphi?

Question

typedef struct _FILE_OBJECTID_INFORMATION {
    LONGLONG FileReference;
    UCHAR ObjectId[16];
    union {
        struct {
           


        

Answer 1

Similar structure can be found in JEDI API Lib:

  _FILE_OBJECTID_BUFFER = record

    //
    //  This is the portion of the object id that is indexed.
    //

    ObjectId: array [0..15] of BYTE;

    //
    //  This portion of the object id is not indexed, it's just
    //  some metadata for the user's benefit.
    //

    case Integer of
      0: (
        BirthVolumeId: array [0..15] of BYTE;
        BirthObjectId: array [0..15] of BYTE;
        DomainId: array [0..15] of BYTE);
      1: (
        ExtendedInfo: array [0..47] of BYTE);
  end;