Mega Code Archive
Use the luxery of TList with Integers (instead of Arrays)
<![CDATA[
Title: use the luxery of TList with Integers (instead of Arrays)
Question: using TList gives you the opportunity to to easy opperations with data like Exchange, Move, Delete, Remove, Add, Insert, First, Last, Sort, Count, .... all of this Array does not support (with the same comforet). Unfortunately enough, TList is used with pointers (eg to Controls)
Here is a way to use Integers with a TList instead of with a TArray.
So you can work much easier with the integers as you work with TList instead of with arrays
Answer:
Why not use TList with all its luxurious operators with Integers
(should work with Floating point-values too. For Strings, you've
got TString to use. TList normally works with pointers (eg for
Controls (TEdit, TBitBtn). We can use TList also with Integers!unit Unit1;
{ using TList gives you the opportunity to to easy opperations with data like
Exchange, Move, Delete, Remove, Add, Insert, First, Last, Sort, Count, ....
all of this Array does not support (with the same comforet).
Unfortunately enough, TList is used with pointers (eg to Controls)
Here is a way to use Integers with a TList instead of with a TArray.
So you can work much easier with the integers as you work with TList instead of
with arrays}
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, Buttons, ComCtrls;
type
TForm1 = class(TForm)
StatusBar1: TStatusBar;
GroupBox1: TGroupBox;
BitBtn1: TBitBtn;
Edit1: TEdit;
GroupBox2: TGroupBox;
GroupBox3: TGroupBox;
GroupBox4: TGroupBox;
Memo1: TMemo;
Memo2: TMemo;
BitBtn2: TBitBtn;
procedure BitBtn1Click(Sender: TObject);
procedure BitBtn2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
type
TMyDataPoint = class
public
Data1: integer;
constructor Create(aData1: integer);
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
constructor TMyDataPoint.Create(aData1: integer);
begin
Data1 := aData1;
end;
procedure TForm1.BitBtn1Click(Sender: TObject);
var MyList : TList;
begin
MyList := TList.Create;
MyList.Add(TMyDataPoint.Create(5));
Statusbar1.Panels[1].Text := inttostr ( TMyDataPoint(MyList.Items[0]).Data1 );
MyList.Free;
end;
procedure TForm1.BitBtn2Click(Sender: TObject);
var i: integer;
MyList : TList;
begin
MyList := TList.Create;
for i:= 0 to Memo1.Lines.Count-1 do
MyList.Add(TMyDataPoint.Create( strtoint ( Memo1.Lines[i])));
Memo2.Clear;
for i:= 0 to Memo1.Lines.Count-1 do
Memo2.Lines.Add ( inttostr( TMyDataPoint(MyList.Items[i]).Data1 ));
MyList.Free;
end;
end.
--------------
The dpr-file:
program TList_Integer;
uses
Forms,
Unit1 in 'Unit1.pas' {Form1};
{$R *.res}
begin
Application.Initialize;
Application.CreateForm(TForm1, Form1);
Application.Run;
end.
------------
the dfm-file:
object Form1: TForm1
Left = 374
Top = 470
Width = 404
Height = 252
Caption = 'Form1'
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 StatusBar1: TStatusBar
Left = 0
Top = 206
Width = 396
Height = 19
Panels = item
Text = 'Dir:\TList_Integer'
Width = 92
end
item
Width = 50
end
item
Text = 'use TList with Integer (insted of TArray)'
Width = 50
end
SimplePanel = False
end
object GroupBox1: TGroupBox
Left = 0
Top = 0
Width = 217
Height = 49
Caption = 'One String only (useless....)'
TabOrder = 1
object BitBtn1: TBitBtn
Left = 8
Top = 16
Width = 75
Height = 25
Caption = 'BitBtn1'
TabOrder = 0
OnClick = BitBtn1Click
end
object Edit1: TEdit
Left = 88
Top = 16
Width = 121
Height = 21
TabOrder = 1
Text = 'Edit1'
end
end
object GroupBox2: TGroupBox
Left = 0
Top = 50
Width = 393
Height = 151
Caption = 'Several Strings'
TabOrder = 2
object GroupBox3: TGroupBox
Left = 8
Top = 16
Width = 185
Height = 105
Caption = 'Read from'
TabOrder = 0
object Memo1: TMemo
Left = 0
Top = 12
Width = 180
Height = 89
Lines.Strings = (
'2'
'32'
'7000'
'9'
'8'
'101')
TabOrder = 0
end
end
object GroupBox4: TGroupBox
Left = 200
Top = 16
Width = 185
Height = 105
Caption = 'Write into'
TabOrder = 1
object Memo2: TMemo
Left = 0
Top = 12
Width = 180
Height = 89
Lines.Strings = (
'Memo2')
TabOrder = 0
end
end
object BitBtn2: TBitBtn
Left = 8
Top = 120
Width = 75
Height = 25
Caption = 'BitBtn2'
TabOrder = 2
OnClick = BitBtn2Click
end
end
end
-----------------
]]>