Mega Code Archive
Delphi trick for implementing VBs Control Arrays
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Title: Delphi trick for implementing VB's Control Arrays
Question: This is a delphi trick for implementing "arrays of components" as used in Visual Basic's "Control Arrays" which allow you to access Controls placed on a form via an index..
Answer:
The example can be applied to any set of component
such as TEdits, or TTables , or TImage etc..
See the example project CAProj as the trick
is explained thoroughly..
Perhaps this trick would help to convert VB Developers
to the exciting world of Delphi ....
By Malek BADI B.Sc.(Eng.) M.Sc.
www.ELMAWRID.com
email: info@ELMAWRID.com
or: Malek_BADI@hotmail.com
============ Example Form Unit Code ==========================================
unit ControlArrayExampleForm;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls;
type
TControlsArrayForm = class(TForm)
Edit1: TEdit;
Edit2: TEdit;
Edit3: TEdit;
Edit4: TEdit;
Edit5: TEdit;
Edit6: TEdit;
Edit7: TEdit;
Edit8: TEdit;
Edit9: TEdit;
Edit10: TEdit;
Button1: TButton;
Button2: TButton;
Label1: TLabel;
GroupBox1: TGroupBox;
Memo1: TMemo;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
// Declare an array of whatever Components you want to handle
// as a collection in an Array
MyEdits : array [1..10] of TEdit;
end;
var
ControlsArrayForm: TControlsArrayForm;
implementation
{$R *.DFM}
procedure TControlsArrayForm.FormCreate(Sender: TObject);
begin
// First Assign Edit1 to Edit10 to corresponding
// elements into the MyEdits Array
MyEdits[1]:=Edit1;
MyEdits[2]:=Edit2;
MyEdits[3]:=Edit3;
MyEdits[4]:=Edit4;
MyEdits[5]:=Edit5;
MyEdits[6]:=Edit6;
MyEdits[7]:=Edit7;
MyEdits[8]:=Edit8;
MyEdits[9]:=Edit9;
MyEdits[10]:=Edit10;
end;
procedure TControlsArrayForm.Button1Click(Sender: TObject);
var i : integer;
begin
for i:=Low(MyEdits) to High(MyEdits) do
MyEdits[i].Text:='Hello from Edit '+inttostr(i)
end;
procedure TControlsArrayForm.Button2Click(Sender: TObject);
var i : integer;
begin
for i:=Low(MyEdits) to High(MyEdits) do begin
MyEdits[i].Text:='Hello I am Edit '+inttostr(i);
MyEdits[i].Font.Style:=[fsBold];
MyEdits[i].Color:=clYellow;
end;
end;
end.
========================== F O R M ====================
object ControlsArrayForm: TControlsArrayForm
Left = 241
Top = 120
Width = 524
Height = 440
Caption = 'Example of Controls Arrays'
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'MS Sans Serif'
Font.Style = []
OldCreateOrder = False
Position = poScreenCenter
OnCreate = FormCreate
PixelsPerInch = 96
TextHeight = 13
object Label1: TLabel
Left = 72
Top = 13
Width = 385
Height = 13
Caption = '(c) Malek BADI , www.ELMAWRID.COM'
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'MS Sans Serif'
Font.Style = [fsBold]
ParentFont = False
end
object Edit1: TEdit
Left = 32
Top = 39
Width = 121
Height = 21
TabOrder = 0
Text = 'Edit1'
end
object Edit2: TEdit
Left = 32
Top = 67
Width = 121
Height = 21
TabOrder = 1
Text = 'Edit2'
end
object Edit3: TEdit
Left = 32
Top = 96
Width = 121
Height = 21
TabOrder = 2
Text = 'Edit3'
end
object Edit4: TEdit
Left = 32
Top = 124
Width = 121
Height = 21
TabOrder = 3
Text = 'Edit4'
end
object Edit5: TEdit
Left = 32
Top = 153
Width = 121
Height = 21
TabOrder = 4
Text = 'Edit5'
end
object Edit6: TEdit
Left = 32
Top = 181
Width = 121
Height = 21
TabOrder = 5
Text = 'Edit6'
end
object Edit7: TEdit
Left = 32
Top = 210
Width = 121
Height = 21
TabOrder = 6
Text = 'Edit7'
end
object Edit8: TEdit
Left = 32
Top = 238
Width = 121
Height = 21
TabOrder = 7
Text = 'Edit8'
end
object Edit9: TEdit
Left = 32
Top = 267
Width = 121
Height = 21
TabOrder = 8
Text = 'Edit9'
end
object Edit10: TEdit
Left = 32
Top = 295
Width = 121
Height = 21
TabOrder = 9
Text = 'Edit10'
end
object Button1: TButton
Left = 32
Top = 334
Width = 217
Height = 25
Caption = 'Perform some Action to Above Controls'
TabOrder = 10
OnClick = Button1Click
end
object Button2: TButton
Left = 32
Top = 367
Width = 217
Height = 25
Caption = 'Do Something Else for Above Controls'
TabOrder = 11
OnClick = Button2Click
end
object GroupBox1: TGroupBox
Left = 168
Top = 43
Width = 305
Height = 263
Caption = 'Example Description :'
TabOrder = 12
object Memo1: TMemo
Left = 11
Top = 28
Width = 281
Height = 206
Color = clInfoBk
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'MS Sans Serif'
Font.Style = []
Lines.Strings = (
'These are 10 TEdits which you'
'can Handle as an Array of Componetst '
'(ie Controls Array as in Visual Basic)'
'After Placing the Components ( i.e. Controls in VBSpeak)'
'on the form , Declare an Array (say MyEdits) with proper '
'dimension of the same type of the controls.'
'In The Create Event of the form you Assign each Array '
'elemnt to the corresponding component'
'Then you can easily handle all components'
'via the Array.. So you can use FOR ..loops, etc...')
ParentFont = False
ReadOnly = True
TabOrder = 0
end
end
end
====================== E N D O F F O R M ===================
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