Home/ Questions/Q 500583
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-13T06:06:08+00:00

I have been tasked with converting an old VB6 program to to C#. One

  • 0

I have been tasked with converting an old VB6 program to to C#. One function I have been having trouble porting over is the calculation of a birthdate from a filed that was read from a binary file:

.BirthDate = CDate((CLng(recPatient.birthDateByte2) * 256) +
                         (recPatient.birthDateByte1 + 366))

The only function I could find that is remotely similar is:

DateTime BirthDate = DateTime.ToDateTime((long)recPatient.birthDateByte2) * 256) 
                                       + (recPatient.birthDateByte1 + 366));

However ToDateTime(long) just returns an InvalidCastException.

Now I can build the string manually but I can not find any documentation anywhere on VB6’s CDate(long).

What am I doing wrong?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Try to use

      DateTime.FromOADate((double)recPatient.birthDateByte2 * 256 
                     + recPatient.birthDateByte1 + 366)

    instead.

    Here is a small piece of documentation about CDate(long). It is not from MS and not about VB6, but since CDate is part of all VBA implementations I have seen so far, I suspect it won’t make a big difference.

    • 0