Import unmanaged code import to delphi from C#

Question

I have a c# class that connects to the dll that works good.

Now I need the same functions in Delphi. what is the best way to do it? I don't want to write all the imports again in Delphi. is there a way to import the c# class in delphi or any other way of doing that quick and easy..

This is one function in my c# class:

    /// Return Type: ABS_STATUS->ABS_LONG->int
    ///pszDsn: ABS_CHAR*
    ///phConnection: ABS_CONNECTION*
    [System.Runtime.InteropServices.DllImportAttribute("bsapi.dll", EntryPoint = "ABSOpen", CallingConvention = System.Runtime.InteropServices.CallingConvention.StdCall)]
    public static extern int ABSOpen([System.Runtime.InteropServices.InAttribute()] [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.LPStr)] string pszDsn, ref uint phConnection);

Yes it's not a .net dll, I think its C++. how wold I import it directly in Delphi, I need to rewrite all the medhods and functions in delphi code?? — Ezi, Apr 19 '12 at 17:52
Yes you must write manually the imports unless it is an activex. — RRUZ, Apr 19 '12 at 17:58

David Heffernan · Accepted Answer · 2012-04-19T19:58:10.760

1

That's simple in Delphi:

function ABSOpen(pszDsn: PAnsiChar; var phConnection: Cardinal): Integer; 
    stdcall; external 'bsapi.dll';

You'll no doubt have more functions than this, but they should all be easy enough. If I were you I would go back to the original C++ header file which should be much easier to translate than your p/invokes.

I don't think there is any good conversion tool for p/invoke to Delphi import unit. Even for C++ header to Delphi, I'm not convinced that there is good universal tool. You can look at the JEDI project which has some useful resources, but in my view it's time to roll up your sleeves!

edited Apr 19 '12 at 19:58

answered Apr 19 '12 at 18:25

David Heffernan

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I have the header file, there is some tool that would do some of the conversion for me? – Ezi Apr 19 '12 at 19:17
I added a link to the JEDI project, which has excellent resources and some tools, but I still think you'll be better doing it manually. The job will be done better that way. – David Heffernan Apr 19 '12 at 19:26
Thank you very much. one thing only.. what is IntPtr in delphi? – Ezi Apr 19 '12 at 19:31
It depends. That's why you need to go back to the header file because you often would translate differently to delphi than for a pinvoke – David Heffernan Apr 19 '12 at 19:33
Read the dr bob article that is linked from the jedi page. Also, how many functions do you need to call? – David Heffernan Apr 19 '12 at 19:40
Not worth trying to use a tool for 5 imports. I've done one for you already! – David Heffernan Apr 19 '12 at 19:48
I don't know why but delphi doesn't like it. the error is: Field definition not allowed after methods or properties – Ezi Apr 19 '12 at 20:00
That's because you are putting the code in my answer inside a class. Don't do that. This is not C# or Java where all methods have to live in classes. Make it a standalone function. – David Heffernan Apr 19 '12 at 20:04
The pointers I don't know how to convert. (I added one function that uses it). – Ezi Apr 19 '12 at 21:19
This is a new question. I answered your first question. – David Heffernan Apr 19 '12 at 21:26
You'll need to include struct definitions in the question – David Heffernan Apr 19 '12 at 21:30
Ok I'll do that in the other question – Ezi Apr 19 '12 at 21:33

Import unmanaged code import to delphi from C#

1 Answers1