关于cm_mouseenter,cmmouseleave

private
  anobject:tobject;
    procedure cmmouseenter(var msg:tmessage); message cm_mouseenter;
    procedure cmmouseleave(var msg:tmessage); message cm_mouseleave;

procedure tcontrolface1.cmmouseenter(var msg:tmessage);
begin
  anobject:=tobject(msg.LParam);
   if anobject<>nil then
    if (anobject.ClassType=tpanel) then
     begin
       tpanel(anobject).BevelInner:=bvraised;
       tpanel(anobject).Color:=clyellow;
     end;
end;

procedure tcontrolface1.cmmouseleave(var msg:tmessage);
begin
  anobject:=tobject(msg.LParam);
   if anobject<>nil then
    if (anobject.ClassType=tpanel) then
      begin
        tpanel(anobject).BevelInner:=bvnone;
        tpanel(anobject).Color:=clmoneygreen;
      end;
end;

  在窗口在放几个tpanel,和一个tgroupbox.

  如果把tpanel放在窗体里,鼠标移到tpanel上有反应(tpanel变成黄色).而如果把tpanel放在

tgroupbox里,则鼠标移到tpanel上就没反应了(tpanel不变色),这是为什么.如何才能让它有反应呢.

CM_XXX是Delphi内部的组件通知消息，MSDN是当然查不到了。