[vtkusers] Question about tcl/tk-VTK application,..

[Barry Hathaway]

Substitution occurs within strings and not within {}s. So instead of:
  button ...  -command {puts $a}
use
  button ... -command "puts $a"
so that the command gets generated as a constant string.

Barry

Miguel Ángel Rodríguez Florido wrote:
>     Hi all,
>
>     Sorry, because this question is more related to tcl/tk, but I know 
> that many people that works under VTK uses Tcl/Tk..so sorry again for 
> people that not.
>
>     My question is very simple, but I haven't found how to do that.
>
>     I have a Tcl/Tk procedure like:
>
>     proc myproc {vars} {
>     
>     code
>     
>       foreach a $list {
>         button .blabla.$a -text $a -command {puts $a}
>       }
>
>     }
>
>
> However the foreach variable $a doesn't exist in the -command option. 
> I mean, I got an error when it runs this puts: puts $a.
>     If I do global this variable: global a, I only got the last value 
> of $a.
>
>     So I understand that the foreach command is running first, and 
> when it finishs, the tcl run the -command option of the tk button.
>
>     How can I access to the variable "a" in the -command button 
> option??. I mean, how can I get the value of "a" at foreach step in 
> the -command option?
>
>     Thank you very much.
>     Best regards.
>