Question

我一直在尝试将一些验证集成到文本输入字段中。

我找到了一个非常有用的帖子here，由用户unbutu创建了一个只能接受字符的文本输入字段：`0123456789。+ - ]。然后我尝试解构代码示例，以便更好地理解它是如何工作的。

我的缩减代码如下，但有几个部分我仍然感到困惑。如果有人能借助他们的智慧来帮助我理解，那我真的很感激。

import tkinter as tk


# Create root window
root = tk.Tk()


class entryWithValidation:
    def __init__(self, parent):

        # Calls the validationFunc function? Why no parenthesis? How do arguments get
        # passed to the function?
        checkFunc = self.validationFunc

        # note 1
        registeredCheckFunc = parent.register(checkFunc)

        # As far as I can tell, this is just a tuple to improve readability.
        # The whole tuple needs to be passed as a single argument to 'validatecommand' 
        shortcut = (registeredCheckFunc,'%d', '%i', '%P', '%s', '%S', '%v', '%V', '%W')

        # creates an entry widget, within 'root', that runs the validation command
        # whenever a key is pressed. The validation command is 'shortcut'
        self.textEntry = tk.Entry(root,
                              validate = 'key',
                              validatecommand = shortcut)

        # Packs entry like normal
        self.textEntry.pack()


    # What are all the arguments for? They don't seem to get used anywhere
    def validationFunc(self, action, index, value_if_allowed,
                 prior_value, text, validation_type,
                 trigger_type, widget_name):

        # However the 'text' argument is passed to this function,
        # it checks the character against the string of valid characters provided,
        # and returns true if present, false if not.
        if text in '0123456789':
            return True
        else:
            return False

entryWithValidation(root)

root.mainloop()

注1：我已经在effbot阅读了文档，但说实话，我无法做出正面或反面。 Tcl包装程序？ Python回调？什么？

苦苦于理解这个Tkinter条目验证码

0 个答案: