[Lazarus] Class operators

[Jose Luis]

On Tue, 2011-05-24 at 00:30 +0200, Mattias Gaertner wrote:
> On Mon, 23 May 2011 18:06:31 -0400
> Jose Luis <jlvolta at fibertel.com.py> wrote:
> 
> > Hi all:
> > 
> > I've tried to cast the argument 'Sender' from a call to an event
> > procedure, but it didn't work. The event is triggered by a TSpeedButton
> > push, and the code of the action call contain the sentence:  
> > 
> > -- if Sender is TSpeedButton then
> > --      buttn:=TSpeedButton(Sender);
> > 
> > The code compile without raising error or warning, but at run-time
> > Sender is not of TSpeedButton's type, like it is in Delphi.
> 
> How do you know that it is not TSpeedButton?
> Please post more code.
> 
>  
> > What's the correct way to cast objects in FPC ?
> 
> The snippet's syntax is correct.
> 
> Mattias
> 
Hi, Mattias, this is the code for that action:

procedure TAyDForm.ButtnBHExecute(Sender: TObject);
var buttn:TSpeedButton;
    indBtn: integer;
    CanChange: boolean;
begin
  if (Sender is TSpeedButton) then
    begin
    bttn:= TSpeedButton(Sender);
    indBtn:=-1;
    repeat
      inc(indBtn);
    until ((bttn.Name = NameButtonSheet[indBtn]) or (indBtn = 17));
    if(indBtn<=17) then
      begin
      CanChange:=true;
      with PageControl1 do
        ActivePage:=Pages[indBtn];
      end;
    end;
end;

The code inside the 'if Sender..' statement is never execute.

J.L.
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