Question

我在限制条目窗口小部件中的字符串长度方面遇到了问题。

我看过几篇关于validatecommand的文章，但并不安静地理解它们。

任何人都可以向我解释如何使用该功能，或者是否还有其他更好的方法可以做到这一点？

我把我的代码放在

之下

from tkinter import *
class Window:
def __init__(self, master):
    self.master = master
    master.title("password")
    master.geometry("1430x1000")
    master.label = Label(master, text="Enter the password and press the button to save it", font=("Times", 30, "bold"), relief=RIDGE, bd=6, bg="grey")
    master.label.grid(row=0, column=1, padx=3, ipadx=3, pady=3, sticky=W+E)
    Ent.entry(master)
    Save.button(master)
    global if_entered
    global password_display
    if_entered = Label(master, text="",font=("Arial", 25) )
    if_entered.grid(row=3, column=1)
    password_display = Label(master, text="", font=("Arial", 25))
    password_display.grid(row=4, column=1)

class Ent:
def entry(self):
    global aa
    aa = StringVar()
    global entered_password
    entered_password = Entry(self, font=("Arial", 30), textvariable=aa)
    entered_password.grid(row=1, column=1)
class Save:
def button(self):
    button_save = Button(self, text="save", command=Save.save_callback)
    button_save.grid(row=2, column=1)
    Label(self, text="Your new password                           :", font=("Arial", 20, "bold")).grid(column=0, row=4, ipadx=0)
def save_callback(self=None):
    global password
    password = aa.get()
    if len(password) <1: #0
        print("A")
        if_entered.configure(text="not entered", font=("Arial", 25))
        if_entered.grid(row=3, column=1)
        password_display.configure(text="none entered",font=("Arial", 25), bg="yellow")
        password_display.grid(row=4, column=1)

    elif len(password) >0: #bigger than 0
        if_entered.configure(text="password saved", font=("Arial",25))
        if_entered.grid(row=3, column=1)
        print(password)
        password_display.configure(text=password, font=("Arial", 25), bg="yellow")
        password_display.grid(row=4, column=1)
root = Tk()
win = Window(root)
root.mainloop()

如何在Tkinter中为条目小部件设置最大长度

0 个答案: