多次验证条目小部件内容中的电子邮件 - tkinter

Question

我有一个正确验证电子邮件的代码，但这种情况只会发生一次。因此，如果电子邮件无效，它不会让我再次验证它。有没有办法一遍又一遍地验证它？

import tkinter as tk
from tkinter import *
from tkinter import ttk
import re

class Test(tk.Frame):
    def __init__(self, root):
        self.root = root
        self.root.geometry("{}x{}+250+150".format(500, 500))
        
        self.entry()

    def testAlphaValue(self, value):
        if value.isalpha():
            return True
        else:
            return False

    def testEmail(self, email):
        regex = '^[a-z0-9]+[\._]?[a-z0-9]+[@]\w+[.]\w{2,3}$'
        wdg = self.wdgLst
        if(re.search(regex, email)):
            return wdg.configure(text='Email is valid')    
        else:
            return wdg.configure(text='Email is invalid')

    def entry(self):
        self.formFrame = LabelFrame(self.root, bg='grey', bd=1)
        self.formFrame.place(x=50, y=50, width=400, height=400)

        regEmail = self.root.register(self.testEmail)
        regAlpha = self.root.register(self.testAlphaValue)

        nameEnt = Entry(self.formFrame)
        nameEnt.config(validate="key", validatecommand=(regAlpha, '%S')) 
        nameEnt.grid(row=0, column=1)

        emailEnt = Entry(self.formFrame)
        emailEnt.config(validate="focusout", validatecommand=(regEmail, '%P'))
        emailEnt.grid(row=0, column=0)
        emailLbl = Label(self.formFrame, text='Email', font=("Helvetica", 8))
        emailLbl.grid(row=1, column=0)
        self.wdgLst = emailLbl

root=tk.Tk()
test = Test(root)
root.mainloop()

谢谢！

Answer 1

我无法解释为什么您的代码不起作用，除非 Entry 小部件必须只允许验证代码运行一次。这可能会满足您的需求。

import tkinter as tk
from tkinter import *
from tkinter import ttk
import re


class Test(tk.Frame):
    def __init__(self, root):
        self.root = root
        self.root.geometry("{}x{}+250+150".format(500, 500))

        self.entry()

    def testAlphaValue(self, value):
        if value.isalpha():
            return True
        else:
            return False

    def testEmail(self, sv):
        email = sv.get()
        regex = '^[a-z0-9]+[\._]?[a-z0-9]+[@]\w+[.]\w{2,3}$'
        wdg = self.wdgLst
        if (re.search(regex, email)):
            return wdg.configure(text='Email is valid')
        else:
            return wdg.configure(text='Email is invalid')

    def entry(self):
        self.formFrame = LabelFrame(self.root, bg='grey', bd=1)
        self.formFrame.place(x=50, y=50, width=400, height=400)

        sv_email = StringVar()
        sv_email.trace("w", lambda name, index, mode,
                                   sv=sv_email: self.testEmail(sv_email))
        regAlpha = self.root.register(self.testAlphaValue)

        nameEnt = Entry(self.formFrame)
        nameEnt.config(validate="key", validatecommand=(regAlpha, '%S'))
        nameEnt.grid(row=0, column=1)

        emailEnt = Entry(self.formFrame)
        emailEnt.config(textvariable=sv_email)
        emailEnt.grid(row=0, column=0)
        emailLbl = Label(self.formFrame, text='Email', font=("Helvetica", 8))
        emailLbl.grid(row=1, column=0)
        self.wdgLst = emailLbl


root = tk.Tk()
test = Test(root)
root.mainloop()

Answer 2

这是一个工作代码，用于验证 focus-out event 上的电子邮件（如您所愿）-（必须阅读代码下方的原因和解释）

import tkinter as tk
from tkinter import *
from tkinter import ttk
import re

class Test(tk.Frame):
    def __init__(self, root):
        self.root = root
        self.root.geometry("{}x{}+250+150".format(500, 500))
        
        self.entry()

    def testAlphaValue(self, value):
        if value.isalpha():
            return True
        else:
            return False
        
    def checkEmail(self, val):
        if re.search(regex, val):
            self.wdgLst.configure(text='Email is valid')
            return True
        else:
            self.wdgLst.configure(text='Email is Invalid')
            return False

    def entry(self):
        self.formFrame = LabelFrame(self.root, bg='grey', bd=1)
        self.formFrame.place(x=50, y=50, width=400, height=400)

        regEmail = self.root.register(self.checkEmail)
        regAlpha = self.root.register(self.testAlphaValue)

        nameEnt = Entry(self.formFrame)
        nameEnt.config(validate="key", validatecommand=(regAlpha, '%S')) 
        nameEnt.grid(row=0, column=1)

        emailEnt = Entry(self.formFrame)
        emailEnt.config(validate="focusout", validatecommand=(regEmail, '%P'))
        emailEnt.grid(row=0, column=0)
        emailLbl = Label(self.formFrame, text='Email', font=("Helvetica", 8))
        emailLbl.grid(row=1, column=0)
        self.wdgLst = emailLbl

root=tk.Tk()
regex = '^[a-z0-9]+[\._]?[a-z0-9]+[@]\w+[.]\w{2,3}$'
test = Test(root)
root.mainloop()

***问题原因 ***

根据我对这个问题的了解，似乎有一个规则是::

The function registered to the validate command must return either True or False.
In any other case, if the function returns something else,  
it DISABLES the validation for the respected widget.

在您的代码中，您将 return wdg.configure(<something here>) 设置为在第一个运行.

后立即禁用验证

如果您想更改方法，也可以使用上面@ShaneLoyd 建议的方法，但如果您只想坚持验证命令，请使用上面的代码。

多次验证条目小部件内容中的电子邮件 - tkinter

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