Trapping button events

[kinabalu]

Hi everyone.
Hope any one can help me with this problem.
I have several buttons in a form. I would like to create a procedure/function that do something when a particular button is clicked. I know that this can be done using "case" but cant figure out how to do it.

TQ

 

[Stretchwickster]

You could maybe stick a number in each button's Tag property and then in the generic onclick event handler (which is assigned to each button's onclick event) write something like:

  case (Sender as TButton).Tag of
    1: ShowMessage('Button 1 clicked');
    2: ShowMessage('Button 2 clicked');
    3: ShowMessage('Button 3 clicked');
    4: ShowMessage('Button 4 clicked');
  end;

Clive

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"To err is human, but to really foul things up you need a computer." (Paul Ehrlich)
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To get the best answers from this forum see: faq102-5096

 

[Griffyn]

you can do what you're after using RTTI

[navy][i]// for automatic syntax highlighting see faq102-6487 
[/i][/navy][b]type[/b]
  TButtonEventType = [b]procedure[/b] [b]of[/b] [b]object[/b];

  TForm1 = [b]class[/b](TForm)
  [b]private[/b]
    [b]procedure[/b] ButtonClick(Sender: TObject);  [navy][i]// attach to each TButton on the form[/i][/navy]
  [navy][i]//snip
[/i][/navy]  [b]published[/b]   [navy][i]// these methods must be published
[/i][/navy]    [b]procedure[/b] Button1Event; 
    [b]procedure[/b] Button2Event;
    [b]procedure[/b] NamedButtonEvent;
  [b]end[/b];
  
[b]implementation[/b]

[b]procedure[/b] ButtonClick(Sender: TObject);
[b]var[/b]
  r : TMethod;
  e : TButtonEventType;
[b]begin[/b]
  [navy][i]// do generic button stuff here
[/i][/navy]  r.Data := Pointer(Self);
  r.Code := Self.MethodAddress(TButton(Sender).Name + [teal]'Event'[/teal]);
  e := TButtonEventType(r);
  e;   [navy][i]// call the published method
[/i][/navy][b]end[/b];

You can also use this technique to call published methods that take parameters. Just modify the TButtonEventType declaration to

TButtonEventType = [b]procedure[/b](AParam1: String; AInt: Integer) [b]of[/b] [b]object[/b];

and change the call to

  e([teal]'String'[/teal], 1);

 

[Griffyn]

oops, while I'm sure you wouldn't have noticed, the ButtonClick method should belong to TForm1 ie.

[b]procedure[/b] TForm1.ButtonClick(Sender: TObject);

 

[kinabalu]

Tq for all the responses. I will try all the suggestions and see which one is better.