如何避免重复打开窗口(50分)

328xy · 2002-08-12

一事件通过：
Form1:=TForm1.Crate(application);
Form1.show;
创建并打开窗口
我如何判断窗口已经创建，避免重复创建和打开同一窗口呢

delphing · 2002-08-12

if assigned(form1) then
showmessage('running');

anqinyun · 2002-08-12

if Form1=nil then
Form1:=TForm1.Crate(application)
else
Form1.show;

娃娃2672 · 2003-08-22

if Formmain.MDIChildCount=0 then
Application.CreateForm(TTypeForm, TypeForm);

lwowo · 2003-08-22

if Application.findcomponent('FormQrGoodsInfo')=nil then
application.createform(tFormQrGoodsInfo,FormQrGoodsInfo);

woyaoying · 2003-08-22

if form1 = nil then
form1 := TForm1.create(self);
Form1.show;