Delphi form menus - user-interface

Question

So I have two menu's. When I click a button on menu 1, it creates menu 2, then menu 1 hides itself. After that I want to go back to menu 1 and hide menu 2.
How do I keep a reference to menu 1 in menu 2? Then if I want to go back to menu 2 I don't want to create a new instance, I want to use the already created one. How do I do that?
I know this may be easy but I find Delphi extremley confusing and can't seem to find a way out of it.
Thanks!

Answer 1

If you mean Main menu when you say "form menu" then you can have only one actual TMainMenu component on a form.
Dynamically creating a new TMainMenu is doable, but involves message handling to postpone the deletion of the exisiting TMainMenu to then be able to create a new one. The reason is that you can not delete a menu in the OnClick handler of one of the menu's items.
Let me suggest an easier way to achieve something similar by hiding / showing branches of a single TMainMenu as follows:
Drop a TMainMenu on the form and write menu items as usual. In my example I created two branches, one named MenuA and the other MenuB. Under these I added menu items, of which the first one (you are free to choose which one you use) activates the other menu branch and hides it's own branch. And visa versa for the other one.
Here's the menu part of the form in text view:
object MainMenu1: TMainMenu
Left = 112
Top = 48
object MenuA: TMenuItem
Caption = 'MenuA'
object Item11: TMenuItem
Caption = 'MenuB'
OnClick = Item11Click
end
object Item12: TMenuItem
Caption = 'Item12'
end
end
object MenuB: TMenuItem
Caption = 'MenuB'
object Item21: TMenuItem
Caption = 'MenuA'
OnClick = Item21Click
end
object Item22: TMenuItem
Caption = 'Item22'
end
object Item23: TMenuItem
Caption = 'Item23'
end
end
end
And here is the code for the menu clicks. Note that I make the second menu branch hidden in the forms OnCreate even. Instead, you can of course set the Visible property to False at design time, in the Object Inspector.
procedure TForm9.FormCreate(Sender: TObject);
begin
MenuB.Visible := False;
end;
procedure TForm9.Item11Click(Sender: TObject);
begin
MenuB.Visible := True;
MenuA.Visible := False;
end;
procedure TForm9.Item21Click(Sender: TObject);
begin
MenuB.Visible := False;
MenuA.Visible := True;
end;