Need help with the variables scope.

[ahmaka]

Hi!
I am new to Tcl/Tk and I need some help .

My procedure is:

proc changeText {data} {
   upvar #0 $data v
   set w .f.f0.u
   set vehicleNum $v(Tag)
	
   # changing the text 
   $w bind $v(Tag) <Button-1>  { 	
            upvar 1 $vehicleNum v 
	    set num $v
            set QuTxt(NumberOfCarsBehind) $num
            }
}

The idea is to take the number of the rectangle when you click on one. But I get an error:
ERROR: can't read "vehicleNum": no such variable

command bound to event:
"upvar 1 $vehicleNum v "



Any ideas ?
Thank you in advance.

 

[Bong]

upvar is, in my opinion, complicated. I think your problem is that you referred to the value of vehicleNum ($vehicleNum), rather than its name (which is vehicleNum) which is what the upvar syntax requires.

I used to try to use scope changes but I've gotten to where I just refer to the variable in the global scope ($::vehicleNum).

_________________
Bob Rashkin