The Wiert Corner – irregular stream of stuff

From a while back, but still interesting especially because there some differences similar to base/inherited designer objects: [WayBack] vcl – How to do bulk -transformation of form to frame- in Delphi? – Stack Overflow:

Observe the differences of a Form and a Frame in your project.

First the project.dpr source:

program Project1;

uses
  Forms,
  Unit1 in 'Unit1.pas' {Form1},
  Unit3 in 'Unit3.pas' {Frame3: TFrame};

{$R *.res}

begin
  Application.Initialize;
  Application.MainFormOnTaskbar := True;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

Differences:

1. Frame as a more elaborated comment to tell the IDE which designer it should use
2. Form can be autocreate

Dfm files:

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 348
  ClientWidth = 643
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  PixelsPerInch = 96
  TextHeight = 13
end

and

object Frame3: TFrame3
  Left = 0
  Top = 0
  Width = 320
  Height = 240
  TabOrder = 0
end

Frame does not have these properties:

• Caption
• ClientHeight
• ClientWidth
• Color
• Font.Charset
• Font.Color
• Font.Height
• Font.Name
• Font.Style
• OldCreateOrder
• PixelsPerInch
• TextHeight

Sidenote: Frame does not have these events:

• OnCreate
• OnDestroy

A Frame has not global variable like this:

var
  Form1: TForm1;

And a Frame descends from TFrame, whereas a form descends from TForm.

Note: with Frame/Form inheritence, your steps become a bit longer.

–jeroen

Some of these are similar to the differences you see here:

• Delphi – Frames as visual Components – changing your inheritance
• Delphi – TInterfacedDataModule revisted – use ‘inherited’ in your .dfm files when your datamodules look like forms in the designer

–jeroen

PS: Idea: make a wizard or conversion tool for this.