OnClick procedure for Control Arrays.
lazarus / 31-LCL

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Hopestation · 2010-10-08 09:49

Hello.

In Delphi4 I can create an array of radio buttons and use a common
OnClickRdBtn call.

Here is my Delphi code:-

uses
..
    procedure RdBtnClick(Sender: TObject);
..
implementation
..
procedure TForm1.FormCreate(Sender: TObject);
Var
  N: Integer;
begin
  For N := 0 to 9 Do
  begin
    RdBtn[N] := TRadioButton.Create(Owner);
    RdBtn[N].Parent := RadioGroup1;
    RdBtn[N].OnClick := RadioButtonClick;
  end;
..
   procedure TForm1.RdBtnClick(Sender: TObject);
Var
  Source: TRadioButton;
  N: Integer;
begin
  Source := TRadioButton(Sender);
  N := Source.Tag;
  Edit1.Text := IntToStr(N);;
end;

This works and operates on the selected button.

When I import it into Lazarus it still works.

When I try to create the form in Lazarus I get the message not enough
paramerters, but nothing to tell me what parameters are required.

Here is my Lazarus code:-

uses
..
    procedure RadioButtonClick(Sender: TObject);
..
implementation
..
procedure TForm1.FormCreate(Sender: TObject);
Var
  N: Integer;
begin
  For N := 0 to 9 Do
  begin
    RdBtn[N] := TRadioButton.Create(Owner);
    RdBtn[N].Parent := RadioGroup1;
    RdBtn[N].OnClick := RadioButtonClick;
  end;
end;
..
procedure TForm1.RadioButtonClick(TRadioButton);
Var
  Source: TRadioButton;
begin
  Frm_Main_1.Edit3.Text := Copy(RadioButton9.Caption,1,1);
end; 

The following messages are displayed:-
type1.pas(58,41) Error: Wrong number of parameters specified for call
to "RadioButtonClick"
type1.pas(18,15) Hint: Found declaration:
TForm1.RadioButtonClick(TObject);
type1.pas(62,47) Fatal: Syntax error, ":" expected but ")" found.

What am I doing wrong?

Thanks
Roger.

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fabienwang · 2010-10-08 09:54

as you defined the method:
procedure TForm1.RadioButtonClick(TRadioButton);

you should add this in the type:

procedure RadioButtonClick(TRadioButton);


OR

you can try
procedure RadioButtonClick(TRadioButton); instead of TForm1.

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eny · 2010-10-08 10:02

Also, try this:

Code: [Select]RdBtn[N].OnClick := @RdBtnClick;
Note the @-symbol.

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Hopestation · 2010-10-09 13:08

Thank you both for your help.

Using @ worked. I don't need this in Delphi4.

Is there a simple explanation of why it is needed in Lazarus?

Regards

Roger

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felipemdc · 2010-10-09 13:17

Free Pascal support various Pascal dialects. If you want to use the
Delphi dialect then you should use the {$mode delphi} directive in
your source code.