挂系统钩子来获得按键消息type
  TForm1 = class(TForm)
.....
  protected:
    hotkeyid:integer;
    procedure WMhotkeyhandle(var msg:tmessage);message wm_hotkey;
end;.....procedure TForm1.FormCreate(Sender: TObject);
begin
  hotkeyid:=globaladdatom(pchar('UserDefineHotKey'))-$c000;
  registerhotkey(handle,hotkeyid,MOD_control,$51);
end;procedure tform1.WMhotkeyhandle(var msg:tmessage);
begin
if (msg.LParamHi=$51) and (msg.lparamLo=mod_control) then
  begin
  msg.Result:=1;
  application.BringToFront;
//someting get focus
  end;
end;procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  unregisterhotkey(handle,hotkeyid);
  DeleteAtom(HotKeyID);
end;