Python GUI程序，两次转换

Question

I was working on designing a program with 2 windows for conversion. One for kilometers to miles, and the other miles to kilometers. The GUI message box has two places to type, but only the kilomiles box gives me results. I've tried different things, but i haven't been able to figure out how to get it so the convert button works for no matter which box I enter in.

import tkinter
import tkinter.messagebox


class MyGUI:
    def __init__(self):

    # Create the main window widget.
    self.main_window = tkinter.Tk()

    # Create two frames
    self.top_frame = tkinter.Frame(self.main_window)
    self.bottom_frame = tkinter.Frame(self.main_window)

    # Create three Label widgets for the
    # top frame.
    self.label1 = tkinter.Label(self.top_frame, \
                                text='Lets Have Fun')
    self.label2 = tkinter.Label(self.top_frame, \
                                text='Calculate Distance')
    self.prompt_label = tkinter.Label(self.top_frame, \
                text='Enter how many kilometers you drove today:')
    self.kilo_entry = tkinter.Entry(self.top_frame, \
                                    width=10)
    self.prompt_label2 = tkinter.Label(self.top_frame, \
                text='Enter how many miles you drove today:')
    self.miles_entry = tkinter.Entry(self.top_frame, \
                                    width=10)
    # Pack the labels that are in the top frame.
    # Use the side='top', 'left' and 'bottom' arguments to stack them
    # one on top of the other.

    self.label1.pack(side='top')
    self.label2.pack(side='top')
    self.prompt_label.pack(side='left')
    self.kilo_entry.pack(side='left')
    self.prompt_label2.pack(side='left')
    self.miles_entry.pack(side='left')


    self.top_frame.pack()
    self.bottom_frame.pack()


    self.my_button = tkinter.Button(self.main_window, \
                                    text='What if I dont know?', \
                                    command=self.do_something)
    self.calc_button = tkinter.Button(self.top_frame, \
                                     text='Convert', \
                                     command=self.convert)
    self.quit_button = tkinter.Button(self.main_window, \
                                      text='Quit', \
                                      command=self.main_window.destroy)

    self.my_button.pack()
    self.quit_button.pack()
    self.calc_button.pack()

    tkinter.mainloop()

def do_something(self):
    tkinter.messagebox.showinfo('Response', \
                                'Just enter your favorite number.')

miles = 0.00
miles == " "




def convert(self):
    # Get the value entered by the user into the
    # kilo_entry widget.
    kilo = float(self.kilo_entry.get())

    # Convert kilometers to miles.
    miles = kilo * 0.6214

    # Display the results in an info dialog box.
    tkinter.messagebox.showinfo('Results', \
        str(kilo) + ' kilometers is equal to ' + \
        str(miles) + ' miles.')
    def convert2(self):
    if self.kilo_entry == " ":
       convert2(self)
    else:
       convert(self)


    tkinter.mainloop()


    # Get the value entered by the user into the
    # kilo_entry widget.
    miles = float(self.miles_entry.get())

    # Convert kilometers to miles.
    kilo = (miles) / (0.6214)

    # Display the results in an info dialog box.
    tkinter.messagebox.showinfo('Results', \
        str(miles) + ' miles is equal to ' + \
        str(kilo) + ' kilo.')

my_gui = MyGUI()

Thank You!

Answer 1

Your code after def do_something(self) is a bit clumsy. In particular, you shouldn't call mainloop() more than once.

One way to implement your convert() method would be to just check if the Input boxes are empty, and convert their content if they are not, as below:

class MyGUI:
    def __init__(self):
        # Create the main window
        self.main_window = tkinter.Tk()

        # Define all widgets
        ...

        # Launch the app
        self.main_window.mainloop()

    def do_something(self):
        tkinter.messagebox.showinfo('Response', \
                                    'Just enter your favorite number.')    

    def convert(self):
        # Convert each box if not empty
        if self.kilo_entry.get() != "":
            self.convert_kilo2miles()
        if self.miles_entry.get() != "":
            self.convert_miles2kilo()

    def convert_kilo2miles(self):
        # Get the value entered by the user into the kilo_entry widget.
        kilo = float(self.kilo_entry.get())

        # Convert kilometers to miles.
        miles = kilo * 0.6214

        # Display the results in an info dialog box.
        tkinter.messagebox.showinfo('Results', \
            str(kilo) + ' kilometers is equal to ' + \
            "{:.3f}".format(miles) + ' miles.')

    def convert_miles2kilo(self):
        # Get the value entered by the user into the miles_entry widget.
        miles = float(self.miles_entry.get())

        # Convert miles to km.
        kilo = (miles) / (0.6214)

        # Display the results in an info dialog box.
        tkinter.messagebox.showinfo('Results', \
            str(miles) + ' miles is equal to ' + \
            "{:.3f}".format(kilo) + ' kilometers.')