Question

delphi7 窗体调用问题

有form1、form2，想在form1里调用form2，当form2关闭后，显示form1，然后再在form1里调用form2，但是程序报错
form1 implementation下面的uses Unit2;
form2 implementation下面的uses Unit1;
form1里有一个Button1Click事件，用来调用form2
procedure Tform1.Button1Click(Sender: TObject);
begin
try
if form2= nil then
begin
form2.Create(Application);//第二次调用form2时此句报错。
end;
finally
FreeAndNil(form2);
end;
end;

procedure Tform2.Button1Click(Sender: TObject);
begin
Application.MessageBox('调用成功！', '提示', 64);
close;
end;

Answer 1

把form1的button1click事件改一下：
procedure TForm1.Button1Click(Sender: TObject);
var
rf:TForm2;
begin
try
if form2= nil then
begin
rf:=TForm2.Create(self);
rf.ShowModal;
rf.Free;
end;
finally
FreeAndNil(form2);
end;
end;

Answer 2

procedure Tform1.Button1Click(Sender: TObject);
var testForm:TForm2;
begin
try
testForm:=TForm2.creat(application);
testForm.modalshow;
finally
FreeAndNil(form2);
end;
end;