# -*- coding: utf-8 -*-
import tkinter as tk
class App:
    def __init__(self, root):
        self.root = root
        self.lbFahrenheit = tk.Label(root, 
            text = '請輸入華氏溫度\n(Fahrenheit)', font="標楷體")
        self.eFahrenheit = tk.Entry(root,
            bg = 'lightgreen', bd = 2, font = "Aharoni", width = 30)
        self.btConversion = tk.Button(root, text = 'Conversion')
        self.lbCentigrade = tk.Label(root, font="Times 18 bold")
        
        self.lbFahrenheit.pack()
        self.eFahrenheit.pack()
        self.btConversion.pack()
        self.lbCentigrade.pack()
        
        self.eFahrenheit.bind('<Return>',self.FtoC)
        self.btConversion.bind('<1>', self.FtoC)
        
    def FtoC(self,event):
        f = float(self.eFahrenheit.get())
        c = (f-32)*5/9
        self.lbCentigrade.config(text = "攝氏{}C".format(c),
            relief = 'raised', height = 2, bg = 'pink', 
            fg = 'blue',font = 'FrankRuehl 12 bold')

def main():
    root = tk.Tk()
    root.title("tk14.py")
    root.geometry("200x200")
    App(root)
    root.mainloop()
    
if __name__=='__main__':
    main()