Delphi 窗体失踪在最上面的代码

unitufrmSysPubMessage;
interface
uses
Windows,Forms,Messages,Classes,ExtCtrls,Controls,StdCtrls;
type
TfrmSysPubMessage=class(TForm)
Image1:TImage;
lblMessage:TLabel;
procedureFormCreate(Sender:TObject);
protected
IconID:PChar;
public
procedureWndProc(varMsg:TMessage);override;
procedureShowMessage(AMsg:string);
end;
implementation
{$R*.DFM}
{TfrmMessageForm}
procedureTfrmSysPubMessage.ShowMessage(AMsg:string);
var
TempWidth:Integer;
begin
lblMessage.Caption:=AMsg;
Application.ProcessMessages;
//调整窗体宽度
TempWidth:=lblMessage.Width+lblMessage.Left+Image1.Left;
ifTempWidth<310then
TempWidth:=310;
Width:=TempWidth;
ifnotVisiblethen
Show;
Application.ProcessMessages;
FormStyle:=fsStayOnTop;
end;
procedureTfrmSysPubMessage.FormCreate(Sender:TObject);
begin
inherited;
IconID:=IDI_ASTERISK;
Image1.Picture.Icon.Handle:=LoadIcon(0,IconID);
//使本窗体始终处于最上面，以免其它窗体挡住它
SetWindowPos(Handle,HWND_TOPMOST,0,0,0,0,SWP_NOMOVEOrSWP_NOSIZE);
end;
procedureTfrmSysPubMessage.WndProc(varMsg:TMessage);
begin
//屏蔽Alt+F4
ifMsg.wParam<>SC_CLOSEthen
inherited;
end;
end.