Создание ловушек в Delphi

Code:

unit MainFormUnit;

interface

uses

Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, Local, global,

StdCtrls;

type

TMainForm = class(TForm)

   Button1: TButton;

   Button2: TButton;

   procedure Button1Click(Sender: TObject);

   procedure FormCreate(Sender: TObject);

   procedure FormDestroy(Sender: TObject);

   procedure Button2Click(Sender: TObject);

private

   { Private declarations }

public

   { Public declarations }

end;

var

MainForm: TMainForm;

implementation

{$R *.DFM}

procedure TMainForm.Button1Click(Sender: TObject);

begin

   if GHookInstalled=true then exit; //if a global hook is installed, exit routine

    //if a local hook not installed, then attempt to install one, else attempt to remove one

    if HookInstalled=false then HookInstalled:=SetupLocalHook else HookInstalled:=not(RemoveLocalHook);

end;

procedure TMainForm.FormCreate(Sender: TObject);

begin

    HookInstalled:=false;

    GHookInstalled:=false;

    LibLoaded:=false;

end;

procedure TMainForm.FormDestroy(Sender: TObject);

begin

    if HookInstalled=true then RemoveLocalHook;

end;

procedure TMainForm.Button2Click(Sender: TObject);

begin

    if HookInstalled=true then exit; //if a local hook is installed, exit routine

    //if a local hook not installed, then attempt to install one, else attempt to remove one

    //note that removelocalhook can still be used no matter whether the hook is global or local

    if GHookInstalled=false then GHookInstalled:=SetupGlobalHook else GHookInstalled:=not(RemoveLocalHook);

end;

end.