The following application I have created is used to demonstrate multiple windows in tkinter. The main problem is that none of the Entry controls, neither in the bmi-calculator or the converter, accept the values in the entry boxes - they get a ValueError when I do a calculation.
from tkinter import *
from tkinter import ttk
from tkinter import messageboxclass App1(ttk.Frame):def createWidgets(self):#text variablesself.i_height = StringVar()self.i_weight = StringVar()self.o_bmi = StringVar()#labelsself.label1 = ttk.Label(self, text="Enter your weight:").grid(row=0, column=0, sticky=W)self.label2 = ttk.Label(self, text="Enter your height:").grid(row=1, column=0, sticky=W)self.label3 = ttk.Label(self, text="Your BMI is:").grid(row=2, column=0, sticky=W)#text boxesself.textbox1 = ttk.Entry(self, textvariable=self.i_weight).grid(row=0, column=1, sticky=E)self.textbox2 = ttk.Entry(self, textvariable=self.i_height).grid(row=1, column=1, sticky=E)self.textbox3 = ttk.Entry(self, textvariable=self.o_bmi).grid(row=2, column=1, sticky=E)#buttonsself.button1 = ttk.Button(self, text="Cancel/Quit", command=self.quit).grid(row=3, column=1, sticky=E)self.button1 = ttk.Button(self, text="Ok", command=self.calculateBmi).grid(row=3, column=2, sticky=E)def calculateBmi(self):try:self.weight = float(self.i_weight.get())self.height = float(self.i_height.get())self.bmi = self.weight / self.height ** 2.0self.o_bmi.set(self.bmi)except ValueError:messagebox.showinfo("Error", "You can only use numbers.")finally:self.i_weight.set("")self.i_height.set("")def __init__(self, master=None):ttk.Frame.__init__(self, master)self.grid()self.createWidgets()class App2(ttk.Frame):def create_widgets(self):"""Create the widgets for the GUI"""#1 textbox (stringvar)self.entry= StringVar()self.textBox1= ttk.Entry(self, textvariable=self.entry).grid(row=0, column=1)#5 labels (3 static, 1 stringvar)self.displayLabel1 = ttk.Label(self, text="feet").grid(row=0, column=2, sticky=W)self.displayLabel2 = ttk.Label(self, text="is equivalent to:").grid(row=1, column=0)self.result= StringVar()self.displayLabel3 = ttk.Label(self, textvariable=self.result).grid(row=1, column=1)self.displayLabel4 = ttk.Label(self, text="meters").grid(row=1, column=2, sticky=W)#2 buttonsself.quitButton = ttk.Button(self, text="Quit", command=self.quit).grid(row=2, column=1, sticky=(S,E))self.calculateButton = ttk.Button(self, text="Calculate", command=self.convert_feet_to_meters).grid(row=2, column=2, sticky=(S,E))def convert_feet_to_meters(self):"""Converts feet to meters, uses string vars and converts them to floats"""self.measurement = float(self.entry.get())self.meters = self.measurement * 0.3048self.result.set(self.meters)def __init__(self, master=None):ttk.Frame.__init__(self, master)self.grid()self.create_widgets()def button1_click():root = Tk()app = App1(master=root)app.mainloop()def button2_click():root = Tk()app = App2(master=root)app.mainloop()def main():window = Tk()button1 = ttk.Button(window, text="bmi calc", command=button1_click).grid(row=0, column=1)button2 = ttk.Button(window, text="feet conv", command=button2_click).grid(row=1, column=1)window.mainloop()if __name__ == '__main__':main()
How can I fix this, but still maintaining the class structure and the use of python3? BTW - Anything similar to C#'s form1.Show()?