Tkinter 输入框总是空的？

Question

所以我正在尝试编写一个根据用户输入更新数据库的程序。该程序首先允许用户使用他们的用户名和密码登录，如果验证成功，那么他们可以在四个选项之间进行选择，put/post/get/delete。我遇到的麻烦是我无法从输入框中获取用户输入。 （我在下面输入了一小段sn-p代码）

#The function that will call my api
def make_get_call(instructorid):
    print(instructorid.get())
    resp = requests.get(url)
    #expecting to get a status of 200 on success
    if resp.json()['status'] != 200:
        print ('Something went wrong {}').format(resp.status_code)
        exit()

    #print data returned
    print ("get succeeded")
    for inspector in resp.json()['response']:
        print (inspector["InspectorID"], str(inspector["InspectorName"]),inspector["Salary"])

#The window that pops up after the user clicks on "get user input" button
def getusers():
    top.withdraw()
    get.deiconify()
    get.geometry('400x150')
    get.title('Getting User Information')

    Label(get, text = "Enter ID of specific inspector").pack(anchor=W)
    id = StringVar()
    Entry(get, textvariable = id).pack(anchor=W)
    Button(get, text="Go", command = partial(make_get_call, id)).pack(anchor=W)

#THe window that pops up after user logs in successfully
def UserPage():
    global top 
    if login:
        tkWindow.withdraw()
        top.deiconify()
        top.geometry('400x150')
        top.title('Valid Input')

        commands = [("Get Information", getusers), ("Update Inspector", updateusers), ("Create User", createuser), ("Delete User", deleteuser)]
        row = 0 
        for command, function in commands:
            Button(top, text = command, command=function).grid(row = row, column = 5)
            row+=4


# Function to validate if user inputed the right username
def validateLogin(username, password):
    global login
    print("Username Entered :", username.get())
    print ("Password Entered: ", password.get())
    data = {"username": username.get(), "password": password.get()}
    #Sending to our API
    resp = requests.get("http://localhost:3001/api/userlogin", json=data)

    #If there is an error
    if resp.json()['status'] != 200:
        messagebox.showerror("Error", "Password/Username wrong. Please Try again")
        exit()

    else:
        login = True
        UserPage()

#THe GUI
tkWindow = Tk()
top = Tk()
top.withdraw()
get = Tk()
get.withdraw()
create = Tk()
create.withdraw()
update = Tk()
update.withdraw()
delete = Tk()
delete.withdraw()

login = False

tkWindow.geometry('400x150')
tkWindow.title('Login Form')

usernameLabel = Label(tkWindow, text = "User Name").grid(row= 0, column=3)
username = StringVar()
usernameEntry = Entry(tkWindow, textvariable = username).grid(row = 0, column=4)

passwordLabel = Label(tkWindow,text="Password").grid(row=1, column=3)  
password = StringVar()
passwordEntry = Entry(tkWindow, textvariable=password, show='*').grid(row=1, column=4)  

validateLogin = partial(validateLogin, username, password)

#login button
loginButton = Button(tkWindow, text="Login", command=validateLogin).grid(row=4, column=3)  


tkWindow = Tk()
top = Tk()
top.withdraw()
get = Tk()
get.withdraw()
tkWindow.mainloop()

主要问题是当用户尝试在输入框中输入特定讲师的 ID 时，当我将 id 变量传递给函数 make_get_call(instructorid) 时，instructorid 始终为空。起初我认为这与延迟有关，例如主循环部分，但我确保将 .get() 放在一个方法中，以便它应该在主循环之后执行。我也尝试将 id 声明为全局变量，但这也没有用。任何帮助将不胜感激！

Answer 1

对不起，我真的剖析了你的代码。

首先，我真的建议使用类而不是全局变量。试试这段代码，它应该是您应用程序其余部分的良好开端。

from tkinter import *
class App(Frame):
    def __init__(self, master):
        super().__init__(master)
        self.master = master
        self.grid(sticky = N+E+S+W)
        self.grid_rowconfigure(0, weight=1)
        self.grid_columnconfigure(0, weight=1) 
        self.createWidgets()

    def createWidgets(self):
        usernameLabel = Label(self.master, text = "User Name").grid(row= 0, column=3)
        self.username = StringVar()
        usernameEntry = Entry(self.master, textvariable = self.username).grid(row = 0, column=4)

        passwordLabel = Label(self.master,text="Password").grid(row=1, column=3)  
        self.password = StringVar()
        passwordEntry = Entry(self.master, textvariable=self.password, show='*').grid(row=1, column=4)  

        # validateLogin = partial(validateLogin, username, password)

        #   login button
        loginButton = Button(self.master, text="Login", command=self.validateLogin).grid(row=4, column=3)  




    # Function to validate if user inputed the right username
    def validateLogin(self):
        global login
        print("Username Entered :", self.username.get())
        print ("Password Entered: ", self.password.get())
        data = {"username": self.username.get(), "password": self.password.get()}


#THe GUI
root = Tk()
root.geometry('400x150')
root.title('Login Form')
tkWindow = App(root)


# login = False


tkWindow.mainloop()