The following example demonstrates trapping the CM_DIALOGCHAR message to surface the accelerator messages for the tab sheets of a PageControl.

Example:
type
  TForm  = class(TForm)
    PageControl : TPageControl;
    TabSheet : TTabSheet;
    TabSheet2: TTabSheet;
    TabSheet3: TTabSheet;
  private
    { Private declarations }
     procedure CMDialogChar(var Msg:TCMDialogChar);
       message CM_DIALOGCHAR;
 public
    { Public declarations }
  end;
var
  Form : TForm ;
implementation
{$R *.DFM}
procedure TForm .CMDialogChar(var Msg:TCMDialogChar);
var
  i:Integer;
begin
  with PageControl  do begin
    if Enabled then
      for i := 0 to PageControl .PageCount -   do
        if ((IsAccel(Msg.CharCode, Pages[i].Caption)) and
            (Pages[i].TabVisible)) then begin
        Msg.Result:= ;
        ActivePage := Pages[i];
        exit;
      end;
  end;
  inherited;
end;