[dpr部分]
program Project1;    uses
  Forms,
  Unit1 in 'Unit1.pas' {Form1}
   ,Windows, Messages;    const
hfck=wm_user $1000;
appname='myname';
var
myhandle:hwnd;
{$R *.res}    begin
myhandle:=findwindow(appname,nil);
if myhandle>0 then
begin
postmessage(myhandle,hfck,0,0);
exit;
end;
  Application.Initialize;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.    [form部分]
unit Unit1;    interface    uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;
const
hfck=wm_user $1000;
appname='myname';
type
  TForm1 = class(TForm)
  private
    { Private declarations }
  public
  procedure createparams(var params:tcreateparams);override;
  procedure restorerequest(var msg:tmessage);message hfck;        { Public declarations }
  end;    var
  Form1: TForm1;    implementation    {$R *.dfm}
 procedure TForm1.createparams(var params:tcreateparams);
 begin
  inherited createparams(params);
  params.WinClassName:=appname;
 end;
  procedure TForm1.restorerequest(var msg:tmessage);
  begin
  if isiconic(application.Handle )=true then
  application.Restore
  else
  application.BringToFront ;      end;
end.