CODEWITHSUNDEEP
python-3.xtkinter
Brad
Brad

Reputation: 1

python3 tkinter, trying to update a label

I've looked at some other answers here, but I'm not understanding how to do this. This is the best I'm coming up with.

To eliminate off-subject comments, i prefer grid over pack, and I also like the widget.configure way of doing things, so that exactly one logical thing is accomplished with each line of code.

towards the end of the code, i have self.root.update() I have also left off the self. with no luck.

from tkinter import *

class Application:
    def __init__(self, master):
        frame1 = Frame(master)
        frame1.grid(row=1, column=1)

        self.btnQuit = Button(frame1)
        self.btnQuit.configure(text="QUIT")
        self.btnQuit.configure(fg="red")
        self.btnQuit.configure(command=frame1.quit)
        self.btnQuit.grid(row=1, column=1)

        self.btnHi = Button(frame1)
        self.btnHi.configure(text="hi there")
        self.btnHi.configure(command="self.hello")
        self.btnHi.grid(row=2, column=1)

        self.lblMessage = Label(frame1)
        self.lblMessage.grid(row=2, column=2)

        def hello(self):
            self.lblMessage.configure(text="hello there")
            self.root.update()

root = Tk()
program = Application(root)
root.mainloop()

Upvotes: 0

Views: 1627

Answers (4)

Richard
Richard

Reputation: 1

Please try this:

from tkinter import *

    class Application:
        def __init__(self, master):
            frame1 = Frame(master)
            frame1.grid(row=1, column=1)

            self.btnQuit = Button(frame1)
            self.btnQuit.configure(text="QUIT")
            self.btnQuit.configure(fg="red")
            self.btnQuit.configure(command=frame1.quit)
            self.btnQuit.grid(row=1, column=1)

            self.btnHi = Button(frame1)
            self.btnHi.configure(text="hi there")
            self.btnHi.configure(command=self.hello)
            self.btnHi.grid(row=2, column=1)

            self.lblMessage = Label(frame1)
            self.lblMessage.grid(row=2, column=2)

        def hello(self):
            self.lblMessage.configure(text="hello there")
            self.root.update()

    root = Tk()`enter code here`
    program = Application(root)
    root.mainloop()

Upvotes: 0

Johan
Johan

Reputation: 21

As stated above:

self.btnHi.configure(command="self.hello")

should be:

self.btnHi.configure(command=self.hello)

and mind the indent of the lines. But also:

self.v = StringVar()
self.lblMessage = Label(frame1, textvariable=self.v)

In your hello method, use:

self.v.set("hello there")

Upvotes: 2

Mayur Patel
Mayur Patel

Reputation: 1025

Not clear to me what you are trying to do, but if you are trying to change the contents of a Label after it is created, then you need to use a StringVar() object. Setting that to the Label's textvariable parameter (in its constructor) will mean that the Label updates whenever you update the value of the StringVar (using its set() method).

Upvotes: 0

user395760
user395760

Reputation:

  1. You have to give the command option a callable object - not a string to be eval'd (which wouldn't work anyway since it'd be in a very different scope, e.g. with no/a different self). http://infohost.nmt.edu/tcc/help/pubs/tkinter/button.html seems to confirm this.
  2. The way your code is indented in your question, you define a local function hello inside __init__ instead of defining it at class level (as a method). You need to remove one level of indentation starting with def hello

Upvotes: 1

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