Writing DLLs in Delphi - Part 1

by Ross Garner, Independent Developer

...That can be Used by C, VB or other Applications.

I have been programming in VB for a number of years and have been tempted to write some of my code using C into a DLL for a couple of reasons:

Unfortunately C seemed to be too hard and I never had the time, or courage, to try. When Delphi came along I thought this could be a solution to my dilemma. However the only Pascal I did was 15 years ago, so I had to go back to basics. Over the next 2 issues of the AVDF I will show the things I have learnt in making DLLs in Delphi and the interface code required for VB. I am sure there are Pascal gurus who could improve my code and I encourage you to participate in this discussion.

Image of 'How To' title The Different Ways of Passing Information
Setting up the Delphi Environment
A DLL Example for Numbers
What Happens if it does not Work?
Major Problems with Functions
Adding Version Information to the DLL

In the next issue of Visual Developers Forum this topic will continue and show the way to transfer:

If you have any comments or improvements please contact the editor via e-mail rgarner@vtrlmel1.oz.au, or phone 61-03 9818 6344.

Written by: Ross Garner
June 95

Image of arrow to previous article Image of arrow to next article