Criar dll

[Joe_m 0]

Estou com o seguinte problema.

 

Tenho uma aplicaçao que rodara com o windows em segundo plano e um leitor de codigo de barra esta ligado a essa maquina. ai o problema essa minha aplicaçao precisa capturar o q o codigo de barra envia, porem a maquina tem que estar livre para ser usada por exemplo se você tiver usando o word e o codigo de barra for ultilizado ele escreve na tela do word.

 

preciso criar uma dll que quando o leitor codigo de barra for utilazado a aplicaçao capture a informaçao independentemente do que esteja sendo feito no pc.

 

essa aplicaçao sera startada com o windows.

[marcio.theis 3]

Ao menos que você consiga monitorar a porta onde estiver conectando o leitor, podendo assim ter controle sobre ele.

[Joe_m 0]

Ao menos que você consiga monitorar a porta onde estiver conectando o leitor, podendo assim ter controle sobre ele.

Grato pela ajuda consegui um dll para controlar isso segue ai se alguem tiver o mesmo problema que eu já vai saber como resolver

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.

////-------------------segunda parte-----------------/////

 

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('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.

 

Ele faz o seguinte:

 

A dll captura a porta do teclado, no meu caso eu precisava capturar o leitor dai criei um codigo de barra especifico da minha aplicação e funciona perfeitamente!!!