到目前为止，我只是想让该程序能够让一个用户登录，我只是一直坚持让他们在登录后打开下一帧。这是我第一次将tkinter与python结合使用，所以我对此不太熟悉。出现的错误是“ File”中的第65行 NameError：名称“ master”未定义”，但我不确定如何解决？预先感谢。
from tkinter import *
import tkinter.messagebox as tm
import tkinter as tk
class SampleApp(tk.Tk):
def __init__(self):
tk.Tk.__init__(self)
self._frame = None
self.switch_frame(StartPage)
def switch_frame(self, frame_class):
new_frame = frame_class(self)
if self._frame is not None:
self._frame.destroy()
self._frame = new_frame
self._frame.pack()
class LoginFrame(tk.Frame):
def __init__(self, master):
tk.Frame.__init__(self, master)
#super().__init__(master)
self.label_username = Label(self, text="Username")
self.label_password = Label(self, text="Password")
self.entry_username = Entry(self)
self.entry_password = Entry(self, show="*")
self.label_username.grid(row=0, sticky=E)
self.label_password.grid(row=1, sticky=E)
self.entry_username.grid(row=0, column=1)
self.entry_password.grid(row=1, column=1)
self.checkbox = Checkbutton(self, text="Keep me logged in")
self.checkbox.grid(columnspan=2)
self.logbtn = Button(self, text="Login", command=self._login_btn_clicked)
self.logbtn.grid(columnspan=2)
self.pack()
def _login_btn_clicked(self):
username = self.entry_username.get()
password = self.entry_password.get()
if username == "user" and password == "password":
tm.showinfo("Login info", "Welcome")
tk.Button(self, text="Go to main page",
command=lambda: master.switch_frame(PageOne)).grid(row=0, sticky=E)
else:
tm.showerror("Login error", "Incorrect username")
class PageOne(tk.Frame):
def __init__(self, master):
tk.Frame.__init__(self, master)
tk.Label(self, text="This is page one").pack(side="top", fill="x", pady=10)
tk.Button(self, text="Return to start page",
command=lambda: master.switch_frame(StartPage)).pack()
root = Tk()
lf = LoginFrame(root)
root.mainloop()