從 Tkinter 輸入框檢索值

Question

我試圖讓 Tkinter 從輸入框中返回值，但我似乎無法讓它工作。

這是我第一次嘗試 Tkinter，s

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\rik\AppData\Local\Programs\Python\Python38-32\lib\tkinter\__init__.py", line 1883, in __call__
    return self.func(*args)
  File "n:\regnskab\Afregning\RIK\Udvikling\gui\app2.py", line 43, in step_1
    periode_2 = get_period(self)
NameError: name 'get_period' is not defined

import tkinter as tk
from tkinter import ttk

class Mainframe(tk.Tk):
    def __init__(self, *args, **kvargs):
        super().__init__(*args, **kvargs)


        self.title("app")

        UserInputFrame(self).grid(row=1, column=0)
        ControlsFrame(self).grid(row=2, column=0)
        ButtonFrame(self).grid(row=3, column=0)


class UserInputFrame(ttk.Frame):
    def __init__(self, container):
        super().__init__(container)

        self.user_input_year = tk.StringVar(value="2021")

        label_entry_year = ttk.Label(self, text="Year")
        self.entry_year = ttk.Entry(self, textvariable=self.user_input_year)

        label_entry_year.grid(row=2, column=0, sticky="W", padx=10, pady=5)
        self.entry_year.grid(row=2, column=1, sticky="EW")

    def get_period(self):
        print(self.entry_year.get())



class ControlsFrame(ttk.Frame):
    def __init__(self, container):
        super().__init__(container)

        step_1_button = ttk.Button(self, text="Step 1", command=self.step_1)


        step_1_button.grid(row=10, column=0, sticky="EW")

    def step_1(self):
        periode_2 = get_period(self)
        print("step 1")



class ButtonFrame(ttk.Frame):
    def __init__(self, container):
        super().__init__(container)

        quit_button = ttk.Button(self, text="Quit", command=quit)
        quit_button.grid(row=4, column=1, sticky="EW")


    def quit(self):
        app.destroy


app = Mainframe()
app.mainloop()

Answer 1

你必須學習OOP:)

get_period() is not standalone function but it is function inside class UserInputFrame and you try to access it in class ControlsFrame . 您不能以這種方式在其他 class 中訪問一個 class 的 function。

您必須獲取UserInputFrame的實例，

    user_input_frame = UserInputFrame(self)
    user_input_frame.grid(row=1, column=0)

將其作為參數發送到ControlsFrame

    ControlsFrame(self, user_input_frame).grid(row=2, column=0)

將其保存在 class 變量中

class ControlsFrame(ttk.Frame):
    def __init__(self, container, user_input_frame):
        super().__init__(container)

        self.user_input_frame = user_input_frame

然后你就可以使用它了

def step_1(self):
    self.user_input_frame.get_period()  # without `self` in `get_period()`

---

或更好的方法

您應該將UserInputFrame分配給Mainframe中的 class 變量

self.user_input_frame = UserInputFrame(self)
self.user_input_frame.grid(row=1, column=0)

然后其他對象（在Mainframe中創建）可以使用self.master訪問Mainframe （這是它的 paret/master），然后他們可以訪問Mainframe中的元素，如self.master.userinputframe

periode_2 = self.master.user_input_frame.get_period() # without `self` in `get_period()`

---

import tkinter as tk
from tkinter import ttk

class Mainframe(tk.Tk):
    def __init__(self, *args, **kvargs):
        super().__init__(*args, **kvargs)

        self.title("app")

        self.user_input_frame = UserInputFrame(self)
        self.user_input_frame.grid(row=1, column=0)

        ControlsFrame(self).grid(row=2, column=0)
        ButtonFrame(self).grid(row=3, column=0)


class UserInputFrame(ttk.Frame):
    def __init__(self, container):
        super().__init__(container)

        self.user_input_year = tk.StringVar(value="2021")

        label_entry_year = ttk.Label(self, text="Year")
        self.entry_year = ttk.Entry(self, textvariable=self.user_input_year)

        label_entry_year.grid(row=2, column=0, sticky="W", padx=10, pady=5)
        self.entry_year.grid(row=2, column=1, sticky="EW")

    def get_period(self):
        #print(self.entry_year.get())
        return self.entry_year.get()



class ControlsFrame(ttk.Frame):
    def __init__(self, container):
        super().__init__(container)

        step_1_button = ttk.Button(self, text="Step 1", command=self.step_1)
        step_1_button.grid(row=10, column=0, sticky="EW")

    def step_1(self):
        # `self.master` gives access to parent object which here is `Masterframe` (because you used `Masterframe` as `self` when you created `ControlsFrame(self)`
        periode_2 = self.master.user_input_frame.get_period() # without `self` in `get_period()`
        print("step 1")



class ButtonFrame(ttk.Frame):
    def __init__(self, container):
        super().__init__(container)

        quit_button = ttk.Button(self, text="Quit", command=self.quit)
        quit_button.grid(row=4, column=1, sticky="EW")

    def quit(self):
        app.destroy()


app = Mainframe()
app.mainloop()

---

順便說一句：在ButtonFrame你忘記了self. 在 app.destroy() 中的command=self.quit和() app.destroy()

---

編輯： @acw1668 注意到 function get_period()不會從條目返回值 - 它只打印它 - 所以它需要return

    def get_period(self):
        return self.entry_year.get()