定义的代码在使用 tkinter 按钮调用之前执行 [重复]

Question

我正在开发一个程序，该程序允许用户存储他们的用户名和密码，并对存储它们的明文进行哈希处理（因此注释掉的哈希代码）。但是，我将 tkinter 用于 GUI，并且我的一个按钮在调用之前运行定义的函数。 （请忽略所有看似随机的 cmets）

import basehash
import tkinter
import tkinter as tk
import os
from tkinter import*
from tkinter import messagebox
from string import ascii_lowercase

userPaths = ['./usernames2.txt', './username.txt', './usernames3.txt']
passPaths = ['./Passwords2.txt', './Passwords.txt', './Passwords3.txt']
#create new doc and assign doc array
# use an array for password of paths where the password is stored on a plaintext file
password = ("test") 
usernameguess1 = ("")
passwordguess1 = ("")
loggedin = 0
activeUser = ""
activeUserNum = 0
hashbase = basehash.base52()

LETTERS = {letter: str(index) for index, letter in enumerate(ascii_lowercase, start=1)} 

def alphabet_position(text):
    text = text.lower()

    numbers = [LETTERS[character] for character in text if character in LETTERS]

    return ''.join(numbers)

def loginpage():

    #Gui Formatting
    root = tkinter.Toplevel()
    root.resizable(width=FALSE, height=FALSE)
    root.title("HasherTest_V0.1 Login")
    root.geometry("300x150")

    #Username and password boxes
    usernametext = tkinter.Label(root, text="Username:")
    usernameguess = tkinter.Entry(root)
    passwordtext = tkinter.Label(root, text="Password:")
    passwordguess = tkinter.Entry(root, show="*")

    usernameguess1 = usernameguess
    def trylogin():
        print ("Logging In...")


        for x in range(0,len(userPaths)):
            #get path data here
            file1 = open(userPaths[x], "r")
            original = file1.read()
            file1.close()
            if original == usernameguess.get():
                userPaths[x] = activeUser
                x = activeUserNum


        file1 = open(passPaths[activeUserNum], "r")
        original = file1.read()
        original = hashbase.unhash(original)
        file1.close()

        if usernameguess.get() == activeUser and alphabet_position(passwordguess.get()) == original:
           print ("Success!")
           messagebox.showinfo("Success ", "Successfully logged in.")
           viewbutton = tkinter.Button(root, text="Veiw Saved Passwords", command=lambda:[root.withdraw()])
           viewbutton.pack()

        else:
            print ("Error: (Incorrect value entered)")
            messagebox.showinfo("Error", "Sorry, but your username or password is incorrect. Try again")
        #login button


    def viewtest():
        if loggedin == 1:
            messagebox.showinfo("Success ", "Loading Passwords")


        else:
            messagebox.showinfo("Error", "You need to sign in first!")



    #login button
    root.deiconify() #shows login window
    attemptlogin = tkinter.Button(root, text="Login", command=trylogin)
    attemptview = tkinter.Button(root, text="View Stored Passwords", command=viewtest)


    usernametext.pack()
    usernameguess.pack()
    passwordtext.pack()
    passwordguess.pack()
    attemptlogin.pack()
    attemptview.pack()
    window.mainloop()

def signuppage():
    root2 = tkinter.Toplevel()
    root2.resizable(width=FALSE, height=FALSE)
    root2.title("HasherTest_V0.1 Login")
    root2.geometry("300x150")
    #Gui Formatting (again)
    root2 = tkinter.Tk()
    root2.resizable(width=FALSE, height=FALSE)
    root2.title("HasherTest_V0.1")
    root2.geometry("300x150")
    #Username and password boxes
    masterusername = tkinter.Label(root2, text="Enter Master Username:")
    masterusernamebox = tkinter.Entry(root2)
    masterpassword = tkinter.Label(root2, text="Enter Master Password:")
    masterpasswordbox = tkinter.Entry(root2, show="*")


    def trysignup(): 

        newuser = str(masterusernamebox.get())

        length = len(userPaths)

        namepath = './usernames3.txt'
        userPaths[length-1] = namepath
        newfile = open(namepath, 'w')
        newfile.write(newuser)
        newfile.close()

        password = str(masterpasswordbox.get())
        numPass = alphabet_position(password)
        print(numPass)

        """hashbase = basehash.base52()
        #not taking numPass as an int
        #run test 328-i
        hashval = hashbase.hash(numPass)
        print(hashval)

        unhashed = hashbase.unhash(hashval)
        print(unhashed)"""

        path = './passwords3.txt'
        newfile = open(path, 'w')
        newfile.write(numPass)
        newfile.close()

        if newuser == "":
            messagebox.showinfo("Error code 0", "No input entered")
        else:
            return 


    #login button
    mastersignupbutton = tkinter.Button(root2, text="Sign Up 1", command=trysignup())
    mastersignupbutton.pack()



    masterusername.pack()
    masterusernamebox.pack()
    masterpassword.pack()
    masterpasswordbox.pack()
    window.mainloop()


window = tkinter.Tk()
window.resizable(width=FALSE, height=FALSE)
window.title("HasherTest_V0.1")
window.geometry("300x150")

loginbutton = tkinter.Button(window, text="Login", command=lambda:[window.withdraw(), loginpage()])
signupbutton = tkinter.Button(window, text="Sign Up", command=lambda:[window.withdraw(), signuppage()])

loginbutton.pack()
signupbutton.pack()

window.mainloop()

如果您运行此代码，然后按注册按钮，然后输入主用户名和密码，它应该将它们都写入记事本文件，如果框中没有任何内容，则给出错误消息。但是，这些功能都不起作用。当用户按下主窗口上的第一个“注册”按钮时，它会运行错误的代码（不知何故）并在它应该之前给出错误代码。当在“输入主用户名和密码”窗口上按下“注册 1”按钮时，错误代码应显示是否有任何内容。我不知道为什么代码会提前运行。有人可以回复原因，甚至是一些固定的代码吗？谢谢，Tf0R24。

Answer 1

创建按钮时，一个常见的错误是在函数名后面加上括号。而不是这个：

mastersignupbutton = tkinter.Button(root2, text="Sign Up 1", command=trysignup())

这样做：

mastersignupbutton = tkinter.Button(root2, text="Sign Up 1", command=trysignup)

完全相同，但在command=trysingup 之后没有括号。如果要调用需要参数的函数，请执行以下操作：

tkinter.Button(master, text="text", command=lambda: function_that_requires_arguments(x, y))

Answer 2

改成

mastersignupbutton = tkinter.Button(root2, text="Sign Up 1", command=trysignup)