Использование функции из DLL

{
Copyright © 1999 by Delphi 5 Developer's Guide - Xavier Pacheco and Steve Teixeira
}

library
 StrSrchLib;

uses

  Wintypes,
  WinProcs,
  SysUtils,
  Dialogs;

type

  { declare the callback function type }
  TFoundStrProc = procedure
(StrPos: PChar); StdCall
;

function
 SearchStr(ASrcStr, ASearchStr: PChar; AProc: TFarProc): Integer;
  stdcall
;
{ This function looks for ASearchStr in ASrcStr. When if finds ASearchStr,
  the callback procedure referred to by AProc is called if one has been
  passed in. The user may pass nil as this parameter. }
var

  FindStr: PChar;
begin

  FindStr := ASrcStr;
  FindStr := StrPos(FindStr, ASearchStr);
  while
 FindStr <> nil
 do

  begin

    if
 AProc <> nil
 then

      TFoundStrProc(AProc)(FindStr);
    FindStr := FindStr + 1;
    FindStr := StrPos(FindStr, ASearchStr);
  end
;
end
;

exports

  SearchStr;
begin


end
.

{
Copyright © 1999 by Delphi 5 Developer's Guide - Xavier Pacheco and Steve Teixeira
}

unit
 MainFrm;

interface


uses

  Windows, Messages, SysUtils, Classes, Graphics, Controls,
  Forms, Dialogs, StdCtrls;

type

  TMainForm = class
(TForm)
    btnCallDLLFunc: TButton;
    edtSearchStr: TEdit;
    lblSrchWrd: TLabel;
    memStr: TMemo;
    procedure
 btnCallDLLFuncClick(Sender: TObject);
  end
;

var

  MainForm: TMainForm;
  Count: Integer;

implementation


{$R *.DFM}

{ Define the DLL's exported procedure }

function
 SearchStr(ASrcStr, ASearchStr: PChar; AProc: TFarProc): Integer; stdcall

  external

'STRSRCHLIB.DLL';

{ Define the callback procedure, make sure to use the StdCall directive }

procedure
 StrPosProc(AStrPsn: PChar); stdcall
;
begin

  inc(Count); // Increment the Count variable.
end
;

procedure
 TMainForm.btnCallDLLFuncClick(Sender: TObject);
var

  S: string
;
  S2: string
;
begin

  Count := 0; // Initialize Count to zero.
  { Retrieve the length of the text on which to search. }
  SetLength(S, memStr.GetTextLen);
  { Now copy the text to the variable S }
  memStr.GetTextBuf(PChar(S), memStr.GetTextLen);
  { Copy Edit1's Text to a string variable so that it can be passed to
    the DLL function }
  S2 := edtSearchStr.Text;
  { Call the DLL function }
  SearchStr(PChar(S), PChar(S2), @StrPosProc);
  { Show how many times the word occurs in the string. This has been
    stored in the Count variable which is used by the callback function }
  ShowMessage(Format('%s %s %d %s', [edtSearchStr.Text, 'occurs', Count,
    'times.']));
end
;

end
.

Другое по теме:

• Надо подключить DLL и использовать некоторые ее функции
• DLL - убийственная утилита
• DLL и ресурсы