Something about LibMaker I forgot to mention.
The libmaker source that ships with Clarion has a couple of problems with “Unmanaged Exports” DLLs. It only works with short filenames and it prefixes the labels with a “\”. These can be easily fixed in the source of LibMaker but I have created a compiled fixed version that should do the job.
Alternatively use the LoadLibrary API to dynamically load the DLL http://www.clarionmag.com/search/find?searchTerm=author%3Asand+loadlib  (sub required).

What?

ClarionMag article –Mixing Clarion with .NET, Part 1

“To call any .NET procedure from Clarion, you have a few choices. You can expose any .NET class to COM, which makes it visible to any COM client. Once you’ve done that, you can either use Clarion’s OLE control or write some Clarion wrapper classes.” “You can also make a Managed C++ wrapper, which is stored inside your .NET assembly. You then call this wrapper the same way you would call an API function.”

Robert Giesecke – C# Project Template for Unmanaged ExportsVisual Studio C# Project Template to “export managed code to native applications without the need of COM registrations”

And finally, a similar technique using Clarion# – http://clarionsharp.com/blog/2011/05/clarion-net-update-2/

Why?

Using .net allows you to tap into the vast amount of examples and libraries available in the .net world to help you create solutions. There is significantly less need to try and take a C++ or C# example and translate it to clarion code and API calls when you can just wrap up the functionality you need in .net and call it from clarion.

Unless you need to embed .net user controls in a clarion window I cannot see any reason not to use the DLLExport technique. It has the advantage that you don’t need to register the .net assembly using regasm.exe and is likely much faster to execute.

Color picker example

This example uses the Zeta Color Editor from an article on The Code Project website. The same editor is used in my InsertClarionColor addin.

ColorPicker.zip – Clarion 8 and Visual studio C# solutions. (one day I will move it to GitHub!)

  1. Create a C# project using the Unmanaged Exports template in visual studio
  2. Export a method that can be called by clarion which handles the calling of the editor dialog
  3. Create a clarion friendly lib file from the .net dll
  4. Create a clarion project to use the dll!