如何在输入GUI中获取浮点数

时间:2018-12-11 13:49:49

标签: python tkinter

我是python的新手,正尝试制作一个简单的转换器应用程序,但我的问题是我不知道如何解决km至m的问题。如果我找出来,我可以找出其余的。提前致谢!这是我的代码

import tkinter from tkinter import ttk

window=tkinter.Tk() 
window.title("Conversion Unit")

labelOne=ttk.Label(window, text='Enter Value') 
labelOne.grid(row=0, column=0) 
to_be_converted=ttk.Combobox(
    values=('mm', 'cm', 'inches', 'feet', 'yards', 'meter', 'km', 'miles'),
    width=10
).grid(row=0, column=2)

labelTwo=ttk.Label(window, text="Equivalent to") 
labelTwo.grid(row=1, column=1) 
converted=ttk.Combobox(
    values=('mm', 'cm', 'inches', 'feet', 'yards', 'meter', 'km', 'miles'),
    width=10
).grid(row=1, column=2)

userName=tkinter.DoubleVar()

userEntry=ttk.Entry(window, width=5, textvariable=userName)
userEntry.grid(row=0, column=1)

def convert():
    if to_be_converted.get=='km' and converted.get=='m':
        labelTwo.configure(text='Value is equivalent to:' + userName.get() * 1000) 
        btn=ttk.Button(window, text='Convert!', command=convert) 
        btn.grid(row=0, column=4)

window.mainloop()

1 个答案:

答案 0 :(得分:1)

这是一个工作版本,有一些更改:

import tkinter
from tkinter import ttk

UNITS = ('mm', 'cm', 'inches','feet', 'yards', 'meter', 'km', 'miles')

window = tkinter.Tk()
window.title("Conversion Unit")

labelOne = ttk.Label(window,text='Enter Value')
labelOne.grid(row=0,column=0)
to_be_converted = ttk.Combobox(values=UNITS, width=10)
to_be_converted.grid(row=0, column=2)

labelTwo = ttk.Label(window, text="Equivalent to")
labelTwo.grid(row=1,column=1)
converted = ttk.Combobox(values=UNITS, width=10)
converted.grid(row=1, column=2)

userName = tkinter.DoubleVar()
userEntry = ttk.Entry(window, width=5, textvariable = userName)
userEntry.grid(row=0, column=1)

def convert():
    if to_be_converted.get() == 'km' and converted.get() == 'meter':
        labelTwo.configure(text='Value is equivalent to:' + str(userName.get()*1000))

btn = ttk.Button(window, text='Convert!', command=convert)
btn.grid(row=0, column=4)

window.mainloop()

.grid()返回无

所以这行:

to_be_converted = ttk.Combobox(values=UNITS, width=10).grid(row=0, column=2 )

必须是:

to_be_converted = ttk.Combobox(values=UNITS, width=10)
to_be_converted.grid(row=0, column=2)

(与converted相同)

.get是绑定方法,而不是属性

所以这行:

if to_be_converted.get == 'km' and converted.get == 'meter':

必须是:

if to_be_converted.get() == 'km' and converted.get() == 'meter':

(并且'm'必须替换为'meter'-或UNITS必须具有'm'而不是'meter')。

无法将字符串与浮点数连接

所以这行:

labelTwo.configure(text='Value is equivalent to:' + userName.get()*1000)

必须是,例如:

labelTwo.configure(text='Value is equivalent to:' + str(userName.get()*1000))