CODEWITHSUNDEEP
delphifreepascallazarusz-order
itsols
itsols

Reputation: 5582

freepascal/delphi components not appearing (z-order issue I think)

I had a PANEL on the form. Then dynamically I create many more panels and place them on the form to look like a menu.

By mistake I deleted the main PANEL. then put it back as a new control.

Now the dynamic buttons don't show. But there's no error. So I'm guessing that the dynamic components are there but invisible (behind the main PANEL).

Is there a way to fix this? I can't seem to find a z-order property for the components.

Please help.

Here's the code segment:

  For MenuItemCount:= 1 to MenuItemLimit Do
      Begin
      MenuButtons[MenuItemCount] := TPanel.Create(Self);
      With MenuButtons[MenuItemCount] do
          begin

            Width:=180 - (10*MenuItem[MenuItemCount].Level);
            Left:=4+10*MenuItem[MenuItemCount].Level;

            Height:=25;
            Top:= 5 + Height * (MenuItemCount-1);
            Color:= clMenu;
            Cursor:=crHandPoint;

            Parent := MenuGroup; //Parent container for the items.

            Caption := MenuItem[MenuItemCount].Title;

      end;//End for

MenuGroup is the parent panel that is placed at design-time.

Upvotes: 0

Views: 880

Answers (1)

GolezTrol
GolezTrol

Reputation: 116120

There is the method SendToBack, which lets you send a control to the back (and its BringToFront counterpart).

But I think it won't solve your problem. The 'Z-order' of components by default is the order in which they are created. The design time panel is created before the dynamic panels, even once you have removed it and put a new one on the form.

What I think happened (though it's a hard guess without seeing your code), is that you tried to find the panel by name, like this:

var
  ParentPanel: TPanel;
  DynamicPanel: TPanel;
begin
  ParentPanel := FindComponent('PanelX') as TPanel;

  DynamicPanel := TPanel.Create(Self);
  DynamicPanel.Parent := ParentPanel;

This would work, but if you remove PanelX, and put in a new panel with a slightly different name, FindComponent won't find the panel and return nil. The DynamicPanels will have nil as a parent, causing them not to show up.

Upvotes: 2

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