如何将tkinter OptionMenu＆Entry小部件的内容保存到文件中？

Question

我试图从一个选项菜单小部件和一个文件上的条目小部件保存用户输入，问题是用户输入的条目小部件没有正确保存。下面是我的代码。

from tkinter import *             

class ComputeTax: 

    def __init__(self, master): 

     self.compute_tax_frame = Frame(master) 
     self.compute_tax_frame.pack() 

     self.tax_status_label = Label(self.compute_tax_frame, text="input tax  status:") 
     self.tax_status_label.grid(row=0, column=0, sticky=E) 
     self.status_option = StringVar(self.compute_tax_frame) 
     self.status_option.set("S") 
     self.tax_status_option = OptionMenu(self.compute_tax_frame, 
              self.status_option, "S", "M", "M1", "M2", "M3", "M4", 
              command=self.save_ts) 
     self.tax_status_option.grid(row=0, column=1, sticky=W) 

     self.monthly_salary_label = Label(self.compute_tax_frame, text="input monthly pay:") 
     self.monthly_salary_label.grid(row=1, column=0, sticky=E) 
     self.salary_input = StringVar(self.compute_tax_frame) 
     self.salary_input.set("0.00") 
     self.monthly_salary_input = Entry(self.compute_tax_frame, 
              textvariable=self.salary_input) 
     self.monthly_salary_input.grid(row=1, column=1) 

     self.calculate_button = Button(self.compute_tax_frame, text="Save &  Calculate now!") 
     self.calculate_button.grid(row=3, columnspan=2) 

    def save_ts(self, value): 

     tax = value 
     pay = self.salary_input.get() 

     with open("monthly_net_pay", "w") as file: 
      file.write("{}\n".format(tax)) 
      file.write("{}\n".format(pay)) 
      file.close() 

frame = Tk() 
a_compute_class = ComputeTax(frame) 
frame.title("Monthly Tax & Net Pay Computation") 
frame.mainloop() 

Answer 1

我看到你的代码有几个问题。其中主要的一个是OptionMenu部件没有command选项/参数，所以command=self.save_ts没有完成任何事情（我有点惊讶的是，没有出现异常，从你试图指定它提出。）

的解决这个问题的方法是在创建calculate_button时使用它。

第二个是save_ts()函数期望value参数，但不会传递给它。要解决该问题，请先从函数def中删除参数，然后从名为status_option的Stringvar小部件中获取所需的值。

这里是你的代码应用了建议的修复：

from tkinter import * 

class ComputeTax: 
    def __init__(self, master): 
     self.compute_tax_frame = Frame(master) 
     self.compute_tax_frame.pack() 

     self.tax_status_label = Label(self.compute_tax_frame, 
             text="input tax status:") 
     self.tax_status_label.grid(row=0, column=0, sticky=E) 
     self.status_option = StringVar(self.compute_tax_frame) 
     self.status_option.set("S") 
     self.tax_status_option = OptionMenu(self.compute_tax_frame, 
              self.status_option, 
              "S", "M", "M1", "M2", "M3", "M4") 
     self.tax_status_option.grid(row=0, column=1, sticky=W) 

     self.monthly_salary_label = Label(self.compute_tax_frame, 
              text="input monthly pay:") 
     self.monthly_salary_label.grid(row=1, column=0, sticky=E) 
     self.salary_input = StringVar(self.compute_tax_frame) 
     self.salary_input.set("0.00") 
     self.monthly_salary_input = Entry(self.compute_tax_frame, 
              textvariable=self.salary_input) 
     self.monthly_salary_input.grid(row=1, column=1) 

     self.calculate_button = Button(self.compute_tax_frame, 
             text="Save & Calculate now!", 
             command=self.save_ts) 
     self.calculate_button.grid(row=3, columnspan=2) 

    def save_ts(self): 
     tax = self.status_option.get() 
     pay = self.salary_input.get() 
     with open("monthly_net_pay", "w") as file: 
      file.write("{}\n".format(tax)) 
      file.write("{}\n".format(pay)) 
#   file.close() # automatic when using `with` 

frame = Tk() 
a_compute_class = ComputeTax(frame) 
frame.title("Monthly Tax & Net Pay Computation") 
frame.mainloop()