将PageControl下放一个panel设置color为clwhite
将Pagecontrol的OwnerDraw设为True
procedure TForm1.PageControl1DrawTab(Control: TCustomTabControl;
  TabIndex: Integer; const Rect: TRect; Active: Boolean);
begin
  Control.Canvas.Brush.Color :=clwhite;
  Control.Canvas.FillRect(rect);
  Control.Canvas.TextOut(5,5,'汉字');
end;