[ClaVahnz]

Hello all, I want to ask, how to delete array.. I mean, I have an array of shapes, and I want to delete them all when I click a button..

This is my listing program, just want to know what must I do with the button to erase the array of shapes..

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls;

type
TForm1 = class(TForm)
Panel1: TPanel;
Button1: TButton;
Shape1: TShape;
Edit1: TEdit;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
procedure hapus(C: array of TShape);
{ Public declarations }
end;

var
Form1: TForm1;
Shape : array of TShape;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var I, kiri, a : integer;
begin
a:=(strtoint(edit1.text)) DIV 2;
hapus(Shape);
SetLength(Shape, a);
kiri := 10;
for I := 0 to a-1 do
begin
Shape[I] := TShape.create(nil);
with Shape[I] do
begin
hide;
parent := Panel1;
width := 100;
height := 120;
left := kiri;
top := 50;
kiri := kiri + 100 + 10;
show;
end;
end;
end;

procedure TForm1.hapus(C: array of TShape);
var
I : integer;
begin
for I := low(C) to High(C) do
begin
C[I].free;
C[I] := nil;
end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin

??????????

end;

end.

[majlumbo]

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls;

type
TForm1 = class(TForm)
  Panel1: TPanel;
  Button1: TButton;
  Shape1: TShape;
  Edit1: TEdit;
  Button2: TButton;
  procedure Button1Click(Sender: TObject);
  procedure Button2Click(Sender: TObject);
private
  Shape: array of TShape; //make your array part of your form's declaration
  { Private declarations }
public
  procedure hapus(C: array of TShape);
  { Public declarations }
end;

var
  Form1: TForm1;
  //Shape : array of TShape; Do not use Global Variables!
implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var 
   I, kiri, a : integer;
begin
   a:=(strtoint(edit1.text)) DIV 2;
   hapus(Shape);
   SetLength(Shape, a);
   kiri := 10;
   for I := 0 to a-1 do
   begin
      Shape[I] := TShape.create(nil);
      with Shape[I] do
      begin
         hide;
         parent := Panel1;
         width := 100;
         height := 120;
         left := kiri;
         top := 50;
         kiri := kiri + 100 + 10;
         show;
      end;
   end;
end;

procedure TForm1.hapus(C: array of TShape);
var
   I : integer;
begin
   //not necessary to do High to Low in this instance
   //but if you were affecting the size of the array
   //in this code, you would need to do.
   //I prefer to do high to low for this reason.
   for I := High(C) downto low(C) do 
   begin
      C[I].free;
      C[I] := nil;
   end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
   Hapus(Shape);//Free all objects from your array.
   SetLength(Shape, 0);//set its length to 0.
end;

You may also want to ensure that the array is emptied and length set to zero when the application terminates (in case your user doesn't click the button).

[ClaVahnz]

Thank you very much Majlumbo,, it works.. Great answer..

Originally Posted by majlumbo

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls;

type
TForm1 = class(TForm)
  Panel1: TPanel;
  Button1: TButton;
  Shape1: TShape;
  Edit1: TEdit;
  Button2: TButton;
  procedure Button1Click(Sender: TObject);
  procedure Button2Click(Sender: TObject);
private
  Shape: array of TShape; //make your array part of your form's declaration
  { Private declarations }
public
  procedure hapus(C: array of TShape);
  { Public declarations }
end;

var
  Form1: TForm1;
  //Shape : array of TShape; Do not use Global Variables!
implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var 
   I, kiri, a : integer;
begin
   a:=(strtoint(edit1.text)) DIV 2;
   hapus(Shape);
   SetLength(Shape, a);
   kiri := 10;
   for I := 0 to a-1 do
   begin
      Shape[I] := TShape.create(nil);
      with Shape[I] do
      begin
         hide;
         parent := Panel1;
         width := 100;
         height := 120;
         left := kiri;
         top := 50;
         kiri := kiri + 100 + 10;
         show;
      end;
   end;
end;

procedure TForm1.hapus(C: array of TShape);
var
   I : integer;
begin
   //not necessary to do High to Low in this instance
   //but if you were affecting the size of the array
   //in this code, you would need to do.
   //I prefer to do high to low for this reason.
   for I := High(C) downto low(C) do 
   begin
      C[I].free;
      C[I] := nil;
   end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
   Hapus(Shape);//Free all objects from your array.
   SetLength(Shape, 0);//set its length to 0.
end;

You may also want to ensure that the array is emptied and length set to zero when the application terminates (in case your user doesn't click the button).