asked on

How can I create a control array?

Well, I believe the title says it all, but though I'll explain myself a little bit more. I'm trying to make a calculator so that every time the user clicks on the numbers (0,1,2,3...9) I want Delphi to call always the same procedure. That procedure would contain a case structure so that it displays in the edit box what number was pressed.

In Visual Basic it would be really almost something like this:

First you create the control arrays and when you double click any button a unique subroutine is created for all.

procedure TfrmCalculus.ButtonClick(Sender: TObject, Index: Integer);
begin
case Index of
0: edtCalculus.Text := edtCalculus.Text + '0';
1: edtCalculus.Text := edtCalculus.Text + '1';
2: edtCalculus.Text := edtCalculus.Text + '2';
3: edtCalculus.Text := edtCalculus.Text + '3';
4: edtCalculus.Text := edtCalculus.Text + '4';
5: edtCalculus.Text := edtCalculus.Text + '5';
6: edtCalculus.Text := edtCalculus.Text + '6';
7: edtCalculus.Text := edtCalculus.Text + '7';
8: edtCalculus.Text := edtCalculus.Text + '8';
9: edtCalculus.Text := edtCalculus.Text + '9';
end; {end case}
end;

I believe the code is OK, but what i really don't know is how to create the control arrays first to make this code work correctly.

Thanks.

mhervais

1) create a new project
2) on the form of the project put 2 buttons and a TEdit

3) double click on the button one
it will open you the source editor at the place where the clicked event is taken care of

write this method :

procedure TForm1.Button1Click(Sender: TObject);
begin
if sender.ClassNameIs('TButton') then
begin
if TButton(sender).Name ='Button1' then
Edit1.Text := '1';
if TButton(sender).Name = 'Button2' then
Edit1.Text := '2';
end;
end;

4) go back to your form and select the second button

5) on the object inspector click the event tab and select the onclicked event with a simple click.

6) a dropdown listbox proposes you the
method you have already written :
TForm1.Button1Click(Sender: TObject);

select it, run your program and enjoy

regards, Marc

ASKER CERTIFIED SOLUTION

aubs

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edey

or a slighty more fleshed out (and automated) version :):

unit Unit1;

interface

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

type
TForm1 = class(TForm)
Edit1: TEdit;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
procedure doBtnClick(Sender: TObject);
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.FormCreate(Sender: TObject);
const
kSpace = 3;
var
ix : integer;
begin
for ix := 0 to 8 do
with TButton.create(self) do
begin
width := 25;
left := kSpace+(ix mod 3)*(width+kSpace);
top := (3-(ix div 3))*(height+kSpace);
caption := intToStr(ix+1);
onClick := doBtnClick;
parent := self;
end;
end;

procedure TForm1.doBtnClick(Sender: TObject);
begin
edit1.text := TButton(sender).caption;
end;

end.

GL
Mike

ps. MHervais, didn't really want to "steal" your idea, but merely ment to show how highly similar objects can be created, placed, event's assigned, and reffered to with minimal code & effort when done as a single task

mhervais

no harm Mike. My concerns was only to give an anwer that works to answer the question in order to demonstrate the topics, not to write the program

regards, Marc

pin_plunder

ASKER

I'm sorry mhervais, your answer was good, but aubs comment was better. I mean he/she wrote what i really wanted to know.

Some comments to make things clearer..
I thought of working with the buttons captions to save some lines of code, but what i didn't know how to refer to each button's caption: Tbutton(Sender).Caption.

That little piece of code was what i needed and aubs provided it. So aubs, and everybody, consider this question answered.