On Wed, 15 Jun 2005 14:31:55 -0500
Phillip Hart <[EMAIL PROTECTED]> wrote:
Hi Phillip,
> #!usr/bin/python
>
> from Tkinter import *
>
> def location(x,y):
> print "I am in row ",x," and column ",y
>
>
> root=Tk()
> root.geometry('300x300')
> can=Canvas(root,width=250, height=250)
>
> bimage=PhotoImage(file='sq1.gif')
>
> b1=Button(can,bg="black",image=bimage,command=location(0,0)).grid(row=0,column=0)
That's an error which frequently happens to Tkinter beginners.
When you assign the button's command like this the command is executed
immediately
after button creation, the correct usage is:
b1 = Button(can, command=location)
without the parentheses; however if you need to pass arguments to the callback,
you can use a lambda expression like this:
b1 = Button(can, command = lambda x=0, y=0 : location(x, y))
Another problem in this line that doesn't matter here, but might cause
confusion later on
is the use of grid() ; note that grid() returns None, so actually you set your
variable
b1 to None which is probably not what you intended; if you need to keep a
reference to
the Button object you need to split the above into two statements:
b1 = Button(can, <opts>)
b1.grid()
If you don't need a reference you can simply do:
Button(can,<opts>).grid(row=0,column=0)
without creating a (quite useless) variable.
I hope this helps
Michael
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