方法一：
function LowLevelKeyboardProc(nCode:integer;WParam:WPARAM;LParam:LPARAM):LRESULT;stdcall;
type
KBDLLHOOKSTRUCT=record
    vkCode:DWORD;
    scanCode:DWORD;
    flags:DWORD;
    time:DWord;
    dwExtraInfo:dword;
end;
var
   fFlag:BOOL;
   p:^KBDLLHOOKSTRUCT;
begin
   result:=0;
   fFlag := false;
   p:=Pointer(LPARAM);
   if (ncode=HC_ACTION) then
   begin
   case wparam of
    WM_KEYDOWN,
    WM_SYSKEYDOWN,
    WM_KEYUP,
    WM_SYSKEYUP:
    fFlag :=(p.vkCode = VK_Lwin) or (p.vkCode = VK_Rwin)or (p.vkCode = VK_apps);
    end;
    end;
    if fFlag = true then
       Result:=1;
    if ncode <> 0 then
       Result := CallNextHookEX(0,ncode,wparam,lparam);
end;

procedure TForm1.Button1Click(Sender: TObject);
const
    WH_KEYBOARD_LL=13;
begin
 setwindowshookexw(WH_KEYBOARD_LL,LowlevelKeyboardproc,hinstance,0);
end;
方法二：
unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    procedure WndProc(var Message: TMessage); override;
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
var
  wm_sock:integer;
  hHandle:HWND;

function LowLevelKeyboardProc(nCode:integer;WParam:WPARAM;LParam:LPARAM):LRESULT;stdcall;
type
KBDLLHOOKSTRUCT=record
    vkCode:DWORD;
    scanCode:DWORD;
    flags:DWORD;
    time:DWord;
    dwExtraInfo:dword;
end;
var
   fFlag:BOOL;
   p:^KBDLLHOOKSTRUCT;
begin
   result:=0;
   fFlag := false;
   p:=Pointer(LPARAM);
   if (ncode=HC_ACTION) then
   begin
   case wparam of
    WM_KEYDOWN,
    WM_SYSKEYDOWN,
    WM_KEYUP,
    WM_SYSKEYUP:
    fFlag :=(p.vkCode = VK_Lwin) or (p.vkCode = VK_Rwin)or (p.vkCode = VK_apps);
    end;
    end;
    if fFlag = true then
    begin
       PostMessage(hHandle,WM_SOCK,0,0);
       Result:=1;
    end;
    if ncode <> 0 then
       Result := CallNextHookEX(0,ncode,wparam,lparam);
end;

procedure TForm1.Button1Click(Sender: TObject);
const
    WH_KEYBOARD_LL=13;
begin
 wm_sock := 0;
 wm_sock := RegisterWindowMessage('wm_sock');
// showmessage(inttostr(wm_sock));
 hHandle := Self.Handle;

 setwindowshookexw(WH_KEYBOARD_LL,LowLevelKeyboardProc,hinstance,0);
end;

procedure TForm1.WndProc(var Message: TMessage);
begin
  if Message.Msg=WM_SOCK then
  begin
     showmessage('用户按下win键');
  end;
  inherited;
end;

end.