Get-access-to-Controls-on-other-forms


            Title: Get access to Controls on other forms
Question: How can I get access to controls on other forms?
Answer:
You can not have code like this working for you:
 form2.ListBox.Items.Add( 'Hello' );
It won't work.
I thought and could not find a solution till I
got an idea: why not define a variable and work with
that. IT WORKS!
Here is the project. You have to create two forms (form1 (unit1.pas)
and form2 (unit2.pas). But all of this, see the dfm-file at the end of
this artxcle...
Here is unit1 (form1):
unit Unit1;
interface
uses
 Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
 ComCtrls, StdCtrls, Buttons, ExtCtrls;
type
 TForm1 = class(TForm)
 BitBtn_AddItemsOnForm2ListBox: TBitBtn;
 EditAddItemsOnForm2ListBox: TEdit;
 StatusBar1: TStatusBar;
 BitBtn_ShowForm2Modal: TBitBtn;
 Panel1: TPanel;
 procedure BitBtn_AddItemsOnForm2ListBoxClick(Sender: TObject);
 procedure BitBtn_ShowForm2ModalClick(Sender: TObject);
 procedure FormClose(Sender: TObject; var Action: TCloseAction);
 procedure FormCreate(Sender: TObject);
 private
 { Private-Deklarationen }
 public
 { Public-Deklarationen }
 end;
var
 Form1: TForm1;
implementation
uses unit2; //unit2 for Form2
var SecondForm: tForm2;
 
{$R *.DFM}
procedure TForm1.BitBtn_AddItemsOnForm2ListBoxClick(Sender: TObject);
begin
 SecondForm.ListBox1.Items.add(EditAddItemsOnForm2ListBox.Text);
end;
procedure TForm1.BitBtn_ShowForm2ModalClick(Sender: TObject);
begin
 SecondForm.ShowModal;
end;
//========================================================================
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
 SecondForm.release;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
 SecondForm := tform2.create(nil);
end;
end.
..........................................................................
........and here you've got unit2.pas (form2):
unit Unit2;
interface
uses
 Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
 StdCtrls, ComCtrls, Buttons;
type
 TForm2 = class(TForm)
 ListBox1: TListBox;
 BitBtn_Exit: TBitBtn;
 StatusBar1: TStatusBar;
 procedure BitBtn_ExitClick(Sender: TObject);
 private
 { Private-Deklarationen }
 public
 { Public-Deklarationen }
 end;
var
 Form2: TForm2;
implementation
{$R *.DFM}
procedure TForm2.BitBtn_ExitClick(Sender: TObject);
begin
 close;
end;
end.
..........................................................................
unit1.dfm is this:
object Form1: TForm1
 Left = 267
 Top = 337
 Width = 261
 Height = 167
 Caption = 'Delphi-programming -- HOW TO'
 Color = clBtnFace
 Font.Charset = DEFAULT_CHARSET
 Font.Color = clWindowText
 Font.Height = -11
 Font.Name = 'MS Sans Serif'
 Font.Style = []
 OldCreateOrder = False
 OnClose = FormClose
 OnCreate = FormCreate
 PixelsPerInch = 96
 TextHeight = 13
 object BitBtn_AddItemsOnForm2ListBox: TBitBtn
 Left = 8
 Top = 8
 Width = 193
 Height = 25
 Caption = '&Add on ListBox1 on Form2'
 TabOrder = 0
 OnClick = BitBtn_AddItemsOnForm2ListBoxClick
 end
 object EditAddItemsOnForm2ListBox: TEdit
 Left = 40
 Top = 40
 Width = 121
 Height = 21
 TabOrder = 1
 Text = 'Item1'
 end
 object StatusBar1: TStatusBar
 Left = 0
 Top = 121
 Width = 253
 Height = 19
 Panels = item
 Text = 'Access Controls on other forms'
 Width = 155
 end
 item
 Text = '(ent.w.Delphi5)'
 Width = 50
 end
 SimplePanel = False
 end
 object BitBtn_ShowForm2Modal: TBitBtn
 Left = 8
 Top = 72
 Width = 97
 Height = 25
 Caption = '&Show Form2'
 TabOrder = 3
 OnClick = BitBtn_ShowForm2ModalClick
 end
 object Panel1: TPanel
 Left = 0
 Top = 104
 Width = 253
 Height = 17
 Align = alBottom
 Caption = 'Dir:\AccessControlsOtherForms'
 TabOrder = 4
 end
end
...........................................................................
you need unit2.dfm, too:
object Form2: TForm2
 Left = 478
 Top = 520
 Width = 250
 Height = 167
 Caption = 'Form2'
 Color = clBtnFace
 Font.Charset = DEFAULT_CHARSET
 Font.Color = clWindowText
 Font.Height = -11
 Font.Name = 'MS Sans Serif'
 Font.Style = []
 OldCreateOrder = False
 PixelsPerInch = 96
 TextHeight = 13
 object ListBox1: TListBox
 Left = 0
 Top = 0
 Width = 241
 Height = 97
 ItemHeight = 13
 TabOrder = 0
 end
 object BitBtn_Exit: TBitBtn
 Left = 0
 Top = 96
 Width = 113
 Height = 25
 Caption = '&Exit'
 TabOrder = 1
 OnClick = BitBtn_ExitClick
 end
 object StatusBar1: TStatusBar
 Left = 0
 Top = 121
 Width = 242
 Height = 19
 Panels = 
 SimplePanel = False
 end
end
.........................................................................
 Code entered with Delphi 5
 by Omer Yasar Can (living in Holland) 
 ALI BABA Computin'
 omercan@home.nl
Forms Delphi
