python calls Delphi to write Dll code samples

First, take a look at the basic structure of the Delphi unit file:

unit Unit1;  // Unit file name  
interface   // This is the interface keyword that identifies the unit file that the file calls  
uses     // A common unit used by a program  
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs; 

type     // The components used by the program are defined here, 1 The classes, and the procedures and events corresponding to the components  
TForm1 = class(TForm) 
private   // Define private variables and private procedures  
  { Private declarations }
public   // Define common variables and common procedures  
  { Public declarations }
end; 
  
var      // Defines the public variables used by the program  
Form1: TForm1; 

implementation // Program code implementation part  

{$R *.dfm}
  
end. 

The Delphi unit is as follows (output ES6en.dll) :

unit hellofun;

interface

function getint():integer;stdcall;
function sayhello(var sname:PAnsiChar):PAnsiChar;stdcall;
implementation

function getint():integer;stdcall;
begin
 result:=888;
end;
function sayhello(var sname:PAnsiChar):PAnsiChar;stdcall;
begin
 sname:='ok!';
 result:='hello,garfield !';
end;

end.

library hello;

{ Important note about DLL memory management: ShareMem must be the
 first unit in your library's USES clause AND your project's (select
 Project-View Source) USES clause if your DLL exports any procedures or
 functions that pass strings as parameters or function results. This
 applies to all strings passed to and from your DLL--even those that
 are nested in records and classes. ShareMem is the interface unit to
 the BORLNDMM.DLL shared memory manager, which must be deployed along
 with your DLL. To avoid using BORLNDMM.DLL, pass string information
 using PChar or ShortString parameters. }

uses
 System.SysUtils,
 System.Classes,
 hellofun in 'hellofun.pas';

{$R *.res}

exports
 getint,
 sayhello;

begin
end.

The call in python is as follows:

import ctypes

def main():
  dll=ctypes.windll.LoadLibrary("hello.dll")
  ri=dll.getint()
  print(ri)

  s=ctypes.c_char_p()
  rs=ctypes.c_char_p()
  rs=dll.sayhello(ctypes.byref(s))
  print(s)
  print(ctypes.c_char_p(rs))

if __name__ == '__main__':
  main()

Run Python and the output is as follows:

>>> 
888
c_char_p(b'ok!')
c_char_p(b'hello,garfield !')
>>> 

Well, we can have python do some of the work in Delphi, or we can have Delphi do some of the work in Python.

The above procedure has been debugged in DelphiXE2 and Python3.2.

conclusion

That's the end of the Dll code example for python calling Delphi, and I hope you found it helpful. Interested friends can continue to refer to other related topics in this site, if there is any deficiency, welcome to comment out. Thank you for your support!