How to use the Sender ?

[Spent]

Can you tell me in the following code how to set the Sender
property?
void __fastcall TForm1::ImageAllClick(TObject *Sender)
{
// how to change the Sender->Tag;

Sender->Tag=3; // Does not works !
}

Thank you !

 

[Cagliostro]

use
((SomeOfYourObjects*) Sender)->Tag. But first you should in some way ensure what the sender os a pointer to an instance of SomeOfYourObjects.

Ion Filipski

ICQ: 95034075
AIM: IonFilipski
filipski@excite.com

 

[Spent]

Thank you.But Can you give me an example ?

 

[Cagliostro]

Look:
((SomeOfYourObjects*) Sender)->Tag = 3;

put the real class name instead of SomeOfYourObjects.

Ion Filipski

ICQ: 95034075
AIM: IonFilipski
filipski@excite.com

 

[Spent]

Thank you Ion.Its working now.

 

[butthead]

((SomeOfYourObjects*) Sender)->Tag = 3;

is the outside set of parentheses necessary or is this
just another way of doing it.

(SomeOfYourObjects*) Sender->Tag = 3;

tomcruz.net

 

[bNasty]

Another set of brackets is needed because it needs to type-cast Sender and not Sender->Tag. Without outside parentheses you would probably see the compiler-error (or at least warning about converting int to pointer or something like that...)

 

[butthead]

I have been using this

TSpeedButton *S;
S = (TSpeedButton*) Sender;
S->Enabled = false;

But I can see where the extra brackets are needed in the other usage.

thanx

tomcruz.net

 

[Cagliostro]

the style of good tone say what is better to use extra brackets. Syntactically and programatically there is correct to not use them, but it is a bad coding style.

Ion Filipski