我如何从 Entry 小部件获取文本？

Question

刚开始学习python，想做一个简单的登录界面。我尝试按照教程进行操作，但由于某种原因，我的代码总是出错。这是错误：第 18 行，在 sign_in print(f"我的用户名是{username.get()}，我的密码是{password.get()}") AttributeError: 'NoneType' 对象没有属性 'get'

from tkinter import *

main_window = Tk()



# ---------- LABELS ----------
Label(main_window, text = "Username: ").grid(row = 0, column = 0)
Label(main_window, text = "Password: ").grid(row = 1, column = 0)

# ---------- TEXT INPUT ----------
username = Entry(main_window, width = 50, borderwidth = 3.5).grid(row = 0, column = 1)
password = Entry(main_window, width = 50, borderwidth = 3.5, show = "*").grid(row = 1, column = 1)

# ---------- METHODS ----------
def sign_in():
    print(f"My username is {username.get()} and my password is {password.get()}")

# ---------- BUTTON ----------
Button(main_window, text = "Sign In", command = sign_in).grid(row = 2, column = 1)

# ---------- MAIN LOOP ----------
main_window.mainloop()

Answer 1

问题是当你定义用户名和密码时，你也在磨它。相反，您应该分别对用户名和密码条目进行网格划分，如下所示：

    from tkinter import *

    main_window = Tk()
    
    
    
    # ---------- LABELS ----------
    Label(main_window, text = "Username: ").grid(row = 0, column = 0)
    Label(main_window, text = "Password: ").grid(row = 1, column = 0)
    
    # ---------- TEXT INPUT ----------
    username = Entry(main_window, width = 50, borderwidth = 3.5) # Remove grid here
    password = Entry(main_window, width = 50, borderwidth = 3.5, show = "*")

    username.grid(row=0, column=1) # grid Entry's seperately
    password.grid(row=1, column=1)
    
    # ---------- METHODS ----------
    def sign_in():
        print(f"My username is {username.get()} and my password is {password.get()}")
    
    # ---------- BUTTON ----------
    Button(main_window, text = "Sign In", command = sign_in).grid(row = 2, column = 1)
    
    # ---------- MAIN LOOP ----------
    main_window.mainloop()

我如何从 Entry 小部件获取文本？

How do i get text from an Entry widget?

python

tkinter

widget

python-3.x