Como criar um controle de acesso usando código de barras?

[Dias Neto 0]

Boa Tarde!

 

Tenho um leitor óptico de código de barras e quero gerar uma aplicação para fazer leitura em crachás.

Alguém pode me dizer o que devo fazer?

 

Agradecido

 

Dias Neto

[Joe_m 0]

Boa Tarde!

 

Tenho um leitor óptico de código de barras e quero gerar uma aplicação para fazer leitura em crachás.

Alguém pode me dizer o que devo fazer?

 

Agradecido

 

Dias Neto

Explique melhor oq você quer fazer? Se for um leitor de codigo de barra convencional você vai precisar criar uma dll para capturar o leitor de codigo de barra, que é o HOOK ou seja a mesma porta do teclado ai vai o codigo:

 

library HOOKLib;

 

uses

Windows,

Messages,

SysUtils;

 

type

PHookRec = ^THookRec;

THookRec = record

AppHnd: Integer;

MemoHnd: Integer;

end;

 

var

Hooked: Boolean;

hKeyHook, hMemo, hMemFile, hApp: HWND;

PHookRec1: PHookRec;

 

function KeyHookFunc(Code, VirtualKey, KeyStroke: Integer): LRESULT; stdcall;

var

KeyState1: TKeyBoardState;

AryChar: array[0..1] of Char;

Count: Integer;

begin

Result := 0;

if Code = HC_NOREMOVE then Exit;

Result := CallNextHookEx(hKeyHook, Code, VirtualKey, KeyStroke);

{I moved the CallNextHookEx up here but if you want to block

or change any keys then move it back down}

if Code < 0 then

Exit;

 

if Code = HC_ACTION then

begin

if ((KeyStroke and (1 shl 30)) <> 0) then

if not IsWindow(hMemo) then

begin

{I moved the OpenFileMapping up here so it would not be opened

unless the app the DLL is attatched to gets some Key messages}

hMemFile := OpenFileMapping(FILE_MAP_WRITE, False, 'Global7v9k');

PHookRec1 := MapViewOfFile(hMemFile, FILE_MAP_WRITE, 0, 0, 0);

if PHookRec1 <> nil then

begin

hMemo := PHookRec1.MemoHnd;

hApp := PHookRec1.AppHnd;

end;

end;

if ((KeyStroke and (1 shl 30)) <> 0) then

begin

GetKeyboardState(KeyState1);

Count := ToAscii(VirtualKey, KeyStroke, KeyState1, AryChar, 0);

if Count = 1 then

begin

SendMessage(hMemo, WM_CHAR, Ord(AryChar[0]), 0);

{I included 2 ways to get the Charaters, a Memo Hnadle and

a WM_USER+1678 message to the program}

PostMessage(hApp, WM_USER + 1678, Ord(AryChar[0]), 0);

end;

end;

end;

end;

 

 

function StartHook(MemoHandle, AppHandle: HWND): Byte; export;

begin

Result := 0;

if Hooked then

begin

Result := 1;

Exit;

end;

if not IsWindow(MemoHandle) then

begin

Result := 4;

Exit;

end;

hKeyHook := SetWindowsHookEx(WH_KEYBOARD, KeyHookFunc, hInstance, 0);

if hKeyHook > 0 then

begin

{you need to use a mapped file because this DLL attatches to every app

that gets windows messages when it's hooked, and you can't get info except

through a Globally avaiable Mapped file}

hMemFile := CreateFileMapping($FFFFFFFF, // $FFFFFFFF gets a page memory file

nil, // no security attributes

PAGE_READWRITE, // read/write access

0, // size: high 32-bits

SizeOf(THookRec), // size: low 32-bits

//SizeOf(Integer),

'Global7v9k'); // name of map object

PHookRec1 := MapViewOfFile(hMemFile, FILE_MAP_WRITE, 0, 0, 0);

hMemo := MemoHandle;

PHookRec1.MemoHnd := MemoHandle;

hApp := AppHandle;

PHookRec1.AppHnd := AppHandle;

{set the Memo and App handles to the mapped file}

Hooked := True;

end

else

Result := 2;

end;

 

function StopHook: Boolean; export;

begin

if PHookRec1 <> nil then

begin

UnmapViewOfFile(PHookRec1);

CloseHandle(hMemFile);

PHookRec1 := nil;

end;

if Hooked then

Result := UnhookWindowsHookEx(hKeyHook)

else

Result := True;

Hooked := False;

end;

 

procedure EntryProc(dwReason: DWORD);

begin

if (dwReason = Dll_Process_Detach) then

begin

if PHookRec1 <> nil then

begin

UnmapViewOfFile(PHookRec1);

CloseHandle(hMemFile);

end;

UnhookWindowsHookEx(hKeyHook);

end;

end;

 

exports

StartHook,

StopHook;

 

begin

PHookRec1 := nil;

Hooked := False;

hKeyHook := 0;

hMemo := 0;

DLLProc := @EntryProc;

EntryProc(Dll_Process_Attach);

end.

 

unit uTeste;

 

interface

 

uses

Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

Dialogs, StdCtrls;

 

type

TForm1 = class(TForm)

Label1: TLabel;

Memo1: TMemo;

Button1: TButton;

Button2: TButton;

procedure Button1Click(Sender: TObject);

procedure Button2Click(Sender: TObject);

private

hLib2: THandle;

DllStr1: string;

procedure DllMessage(var Msg: TMessage); message WM_USER + 1678;

end;

 

var

Form1: TForm1;

 

implementation

 

{$R *.dfm}

 

procedure TForm1.DllMessage(var Msg: TMessage);

begin

if (Msg.wParam = 8) or (Msg.wParam = 13) then Exit;

{the 8 is the Backspace and the 13 if the Enter key, You'll need to

do some special handleing for a string}

DllStr1 := DllStr1 + Chr(Msg.wParam);

label1.Caption := DllStr1;

end;

 

 

procedure TForm1.Button1Click(Sender: TObject);

type

TStartHook = function(MemoHandle, AppHandle: HWND): Byte;

var

StartHook1: TStartHook;

SHresult: Byte;

begin

hLib2 := LoadLibrary('F:\KEYBOARD\HookLib.dll');

@StartHook1 := GetProcAddress(hLib2, 'StartHook');

if @StartHook1 = nil then Exit;

SHresult := StartHook1(Memo1.Handle, Handle);

if SHresult = 0 then ShowMessage('the Key Hook was Started, good');

if SHresult = 1 then ShowMessage('the Key Hook was already Started');

if SHresult = 2 then ShowMessage('the Key Hook can NOT be Started, bad');

if SHresult = 4 then ShowMessage('MemoHandle is incorrect');

end;

 

procedure TForm1.Button2Click(Sender: TObject);

 

type

TStopHook = function: Boolean;

var

StopHook1: TStopHook;

begin

@StopHook1 := GetProcAddress(hLib2, 'StopHook');

if @StopHook1 = nil then

begin

ShowMessage('Stop Hook DLL Mem Addy not found');

Exit;

end;

if StopHook1 then

ShowMessage('Hook was stoped');

FreeLibrary(hLib2);

{for some reason in Win XP you need to call FreeLibrary twice

maybe because you get 2 functions from the DLL? ?}

FreeLibrary(hLib2);

end;

 

end.

 

com esses dois fontes você vai conseguir capturar o leitor

[marcio.theis 3]

Se você instalar certinho o leitor de código de barras no micro, pode depois somente ler os código de barras dos crachás, ele vai converter as barras em informações que você mandou gravar nelas, podendo manipular assim conforme necessidade.

[Dias Neto 0]

Vou tentar fazer.

 

 

Agradeço a atenção.