Question

在此代码中：

class ButtonBox(tk.Frame):

    def __init__(self, parent):
        tk.Frame.__init__(self, parent)
        self.parent = parent

        shift = tk.Frame(self)
        shift.grid(row = 0, column = 0)

        shiftLabel = ttk.Label(shift, text = "Shift:")
        shiftLabel.grid(row = 0, column = 0)
        amountShift = ttk.Entry(shift, width = 5)
        amountShift.grid(row = 0, column = 1)

        encryptButton = ttk.Button(self, text = "Encrypt")
        encryptButton.grid(row = 0, column = 2)

        decryptButton = ttk.Button(self, text = "Decrypt")
        decryptButton.grid(row = 0, column = 3)
class MainWindow(tk.Frame):

    def __init__(self, parent):
        tk.Frame.__init__(self, parent)
        self.parent = parent
        self.model = Model()


        self.UserIO = TextIO(self)
        self.UserIO.grid(row = 0, column = 0)
        self.Buttons = ButtonBox(self)
        self.Buttons.grid(row = 1, column = 0)
        self.Buttons.encryptButton.config(command =  self.model.encrypt)
        self.Buttons.decryptButton.config(command =  self.model.decrypt)


    def Encrypt():
        message = self.UserIO.inputString.get()
        shift = int(self.Buttons.shift.get())
        self.model.encrypt(message, shift)

    def Decrypt():
        message = self.UserIO.inputString.get()
        shift = int(self.Buttons.shift.get())
        self.model.decrypt(message, shift)


root = tk.Tk()
root.resizable(width = False, height = False)
MainWindow(root).pack()
root.mainloop()

我创建一个MainWindow（），然后向Button对象中的Button添加一个命令。但是，它会产生错误，

Traceback (most recent call last):
  File "/home/pi/Documents/Code Projects/Caesar Cipher.py", line 120, in <module>
    MainWindow(root).pack()
  File "/home/pi/Documents/Code Projects/Caesar Cipher.py", line 103, in __init__
    self.Buttons.encryptButton.config(command =  self.model.encrypt)
AttributeError: 'ButtonBox' object has no attribute 'encryptButton'

，为什么会这样？我创建了一个ButtonBox对象，所以我不明白为什么这不起作用。

Answer 1

您需要在self.encryptButton中使用ButtonBox.__init__而不是encryptButton。您在encryptButton函数中创建了一个局部变量__init__，该变量在外部无法访问。

def __init__(self, parent):
    tk.Frame.__init__(self, parent)
    …
    self.encryptButton = ttk.Button(self, text = "Encrypt")
    self.encryptButton.grid(row = 0, column = 2)
    …

找不到类中的属性

1 个答案: