Tkinter按钮绑定问题

Question

My goal is to eventually have a few labels and entries that appear and correspond with the different days of the week. I am currently working on getting the button binding to generate a different label depending on which day of the week is selected. It's sort of working, but not how I expected and not how I really want. Right now I have to click on a button twice for it to update the label. I'm still pretty new to programming and I appreciate any help you can provide!

root = Tk()
root.geometry('300x300')
root.title('Day')

frame3 = Frame(root)
frame4 = Frame(root)
frame3.grid()

dayFrame = Frame(frame4)
class App(Frame):
    def __init__(self, master):
        Frame.__init__(self, master)
        self.var1 = StringVar()
        self.var1.set('')
        self.sunBtn = Button(frame3, text='Sunday', command=lambda day='Sunday': self.var1.set(day))
        self.sunBtn.bind('<Button-1>', self.openFrame)
        self.sunBtn.grid(row=1, column=0)
        self.monBtn = Button(frame3, text='Monday', command=lambda day='Monday': self.var1.set(day))
        self.monBtn.bind('<Button-1>', self.openFrame)
        self.monBtn.grid(row=1, column=1)

    def openFrame(self,*args):
        frame4.grid()
        dayFrame.grid()
        dayLbl = Label(dayFrame, text=self.var1.get())
        dayLbl.grid(row=1, column=0)

app = App(root)
app.mainloop()

UPDATE: I realized my mistake. I feel dumb. I replaced

self.var1.set('')

with

self.var1.trace('w', self.openFrame)

and it seems like everything is working properly. Hopefully this can help another beginner at some point!

Answer 1

Don't use bind and command at the same time: (and don't forget to write your import line)

from tkinter import *

root = Tk()
root.geometry('300x300')
root.title('Day')

frame3 = Frame(root)
frame4 = Frame(root)
frame3.grid()

dayFrame = Frame(frame4)
class App(Frame):
    def __init__(self, master):
        Frame.__init__(self, master)
        self.var1 = StringVar()
        self.var1.set('')
        self.sunBtn = Button(frame3, text='Sunday', command= lambda: self.openFrame('Sunday'))
        self.sunBtn.grid(row=1, column=0)
        self.monBtn = Button(frame3, text='Monday', command=lambda: self.openFrame('Monday'))
        self.monBtn.grid(row=1, column=1)

    def openFrame(self, day):
        frame4.grid()
        dayFrame.grid()
        dayLbl = Label(dayFrame, text=day)
        dayLbl.grid(row=1, column=0)

app = App(root)
app.mainloop()

A very different (and probably better) solution:

from tkinter import *
import calendar

root = Tk()
root.geometry('600x300')
root.title('Day')

frame3 = Frame(root)
frame4 = Frame(root)
frame3.grid()

dayFrame = Frame(frame4)
class App(Frame):
    def __init__(self, master):
        Frame.__init__(self, master)        
        frame4.grid()
        dayFrame.grid()
        self.dayLbl = Label(dayFrame, text="")
        self.dayLbl.grid(row=1, column=0)
        for i,  day in enumerate(calendar.day_name):
            button = Button(frame3, text=day, command= lambda day=day:\
                self.dayLbl.configure(text=day))
            button.grid(row=1, column=i)         

app = App(root)
app.mainloop()