/////////////////////通用子窗体开关

/////////////////////通用子窗体开关
procedure OpenForm(FormClass: TFormClass; var AForm;
    AOwner:TComponent=nil);
var
  i: integer;
  Child:TForm;
begin
  for i := 0 to Screen.FormCount -1  do
    if Screen.Forms[i].ClassType=FormClass then
      begin
        Child:=Screen.Forms[i];
        if Child.WindowState=wsMinimized then
           Child.WindowState:=wsNormal;
        Child.BringToFront;
        Child.Setfocus;
        TForm(AForm):=Child;
        exit;
      end;
  Child:=TForm(FormClass.NewInstance);
  TForm(AForm):=Child;
  if not assigned(aowner) then aowner:=application;
  Child.Create(AOwner);
end;
////////////
使用：OpenForm(TForm1,Form1);