MRAB於 2019年6月2日星期日 UTC+8上午10時18分36秒寫道：
> On 2019-06-02 02:28, jf...@ms4.hinet.net wrote:
> > Below is a simplified version of the sample script downloaded from its
> > package.
> > When run it, the entry field display '0' instead of 'P&W'.
> > PS. I am using Python 3.4.4, Windows 32bit
> >
> > ----test0.py----
> > 1 from tkinter import tix as Tix
> > 2
> > 3 root = Tix.Tk()
> > 4
> > 5 demo_maker = Tix.StringVar()
> > 6 demo_maker.set('P&W')
> > 7
> > 8 c = Tix.Control(root, label='Engine Maker: ',
> > 9 variable=demo_maker,
> > 10 options='entry.width 10 label.width 20 label.anchor e')
> > 11 c.pack(side=Tix.TOP, anchor=Tix.W)
> > 12
> > 13 root.mainloop()
> > --------
> >
> > I run it under pdb, try to figure out where the problem is:
> >
> > D:\Works\Python>py -m pdb test0.py
> >> d:\works\python\test0.py(1)<module>()
> > -> from tkinter import tix as Tix
> > (Pdb) tbreak 13
> > Breakpoint 1 at d:\works\python\test0.py:13
> > (Pdb) cont
> > Deleted breakpoint 1 at d:\works\python\test0.py:13
> >> d:\works\python\test0.py(13)<module>()
> > -> root.mainloop()
> > (Pdb) !c['value']
> > '0'
> > (Pdb) !demo_maker.get()
> > 'P&W'
> > (Pdb) quit
> >
> > If I change line 8 to "c = Tix.Control(root, label='Engine Maker: ',
> > value='P&W',", the result is very interest:
> >
> > D:\Works\Python>py -m pdb test0.py
> >> d:\works\python\test0.py(1)<module>()
> > -> from tkinter import tix as Tix
> > (Pdb) tbreak 13
> > Breakpoint 1 at d:\works\python\test0.py:13
> > (Pdb) cont
> > Deleted breakpoint 1 at d:\works\python\test0.py:13
> >> d:\works\python\test0.py(13)<module>()
> > -> root.mainloop()
> > (Pdb) !c['value']
> > '0'
> > (Pdb) !demo_maker.get()
> > '0'
> > (Pdb) quit
> >
> > Anyone can help?
> >
> From the documentation:
>
> """class tkinter.tix.Control
> The Control widget is also known as the SpinBox widget. The user can
> adjust the value by pressing the two arrow buttons or by entering the
> value directly into the entry. The new value will be checked against the
> user-defined upper and lower limits."""
>
> In other words, the widget that you're using is for entering a _number_;
> you can click the up and down buttons to change its value. You usually
> use it with tix.IntVar.
>
> You're using it with tix.StringVar, which is for strings, and because
> it's unable to interpret the value as a number, it's pretending that
> it's 0 instead. You can, however, set it to, say, '1', or '01', and the
> widget will then show the number 1.
From the documents, it sounds that this widget was designed for number only.
But the original example Control.py from
https://svn.python.org/projects/stackless/trunk/Demo/tix/samples/ works on
string either by changing its button command. The only thing bothers me is that
why it fails at the start-up? and I can't figure out the reason:-(
--
https://mail.python.org/mailman/listinfo/python-list
