unit UFrmMain;

interface

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

type
  TForm1 = class(TForm)
    btnClose: TButton;
    btnSetHook: TButton;
    btnSizeLongInt: TButton;
    procedure btnCloseClick(Sender: TObject);
    procedure btnSetHookClick(Sender: TObject);
    procedure btnSizeLongIntClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
var
    hHookKeyboard : HHOOK;

procedure TForm1.btnCloseClick(Sender: TObject);
begin
    close;
end;

function MouseHook(code: Integer; wparam: WPARAM; lparam: LPARAM): LRESULT stdcall;
begin
    result := 1;
end;

function KeyHook(code: Integer; wparam: WPARAM; lparam: LPARAM): LRESULT stdcall;
begin
    if (wparam = vk_f4) and ((lparam and (1 shl 29)) > 0) then
        result := 1
    else
        result := CallNextHookEx(hHookKeyboard, code, wparam, lparam);
end;

procedure TForm1.btnSetHookClick(Sender: TObject);
begin
    SetWindowsHookEx(WH_MOUSE,@MouseHook,HInstance,GetCurrentThreadId());
    hHookKeyboard := SetWindowsHookEx(WH_KEYBOARD,@KeyHook,HInstance,GetCurrentThreadId());
end;

procedure TForm1.btnSizeLongIntClick(Sender: TObject);
begin
    ShowMessageFmt(‘sizeof longint:%d‘,[sizeof(longint)]);
end;

end.

//HookLibInterface.pas
unit HookLibInterface;

interface
USES
    windows;
{$IFNDEF HookLibInterface}
    procedure SetHook(hwnd1:HWND); stdcall;
    procedure UnHook(); stdcall;
{$ENDIF}

implementation
{$IFNDEF HookLibInterface}
    procedure SetHook(hwnd1:HWND); external ‘HookLib.dll‘ name ‘SetHook‘;
    procedure UnHook(); external ‘HookLib.dll‘ name ‘UnHook‘;
{$ENDIF}

end.

//HookLib.dpr
library HookLib;

{ 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
  SysUtils,
  Classes,
  Windows,
  Messages,
  Dialogs,
  HookLibInterface in ‘HookLibInterface.pas‘;

{$R *.res}
var
    hMouseHook : HHOOK;
    hKeyboardHook : HHOOK;
var
    g_hwnd : HWND;
    
function MouseHookProc(code: Integer; wparam: WPARAM; lparam: LPARAM): LRESULT stdcall;
begin
    result := 1;
end;
function KeyboardHookProc (code: Integer; wparam: WPARAM; lparam: LPARAM): LRESULT stdcall;
begin
    if vk_f2 = wparam then
    begin
        PostMessage(g_hwnd,wm_close,0,0);
        //UnhookWindowsHookEx(hMouseHook);
        UnhookWindowsHookEx(hKeyboardHook);
    end;
    result := 1;
end;

procedure SetHook(hwnd1 : HWND); stdcall;
begin
    g_hwnd := hwnd1;
    //hMouseHook := SetWindowsHookEx(WH_MOUSE, MouseHookProc, GetModuleHandle(‘HookLib.dll‘),0);
    hKeyboardHook := SetWindowsHookEx(WH_KEYBOARD, KeyboardHookProc, GetModuleHandle(‘HookLib.dll‘),0);
    showmessage(‘成功加载勾子程序!‘);
end;

procedure UnHook(); stdcall;
begin
    //UnhookWindowsHookEx(hMouseHook);
    UnhookWindowsHookEx(hKeyboardHook);
    showmessage(‘成功取消勾子程序!‘);
end;
exports
    SetHook,
    Unhook;
end.

unit UMain;

interface

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

type
  TFrmMain = class(TForm)
    btnClose: TButton;
    btnHookMouse: TButton;
    btnUnHookMouse: TButton;
    procedure btnCloseClick(Sender: TObject);
    procedure btnHookMouseClick(Sender: TObject);
    procedure btnUnHookMouseClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  FrmMain: TFrmMain;

implementation
uses
    HookLibInterface;
{$R *.dfm}

procedure TFrmMain.btnCloseClick(Sender: TObject);
begin
    close;
end;

procedure TFrmMain.btnHookMouseClick(Sender: TObject);
begin                         
    SetHook(application.Handle);
end;

procedure TFrmMain.btnUnHookMouseClick(Sender: TObject);
begin
    UnHook;
end;

procedure TFrmMain.FormCreate(Sender: TObject);
begin
    SetWindowPos(self.Handle,HWND_TOPMOST,0,0,screen.Width,Screen.Height,SWP_SHOWWINDOW	);
end;

end.