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我试图（在运行时）为tkinter.Text的子类替换继承的insert()方法。替换方法在调用父类的 (tkinter.Text) insert() 方法之前执行几行代码。但是，在运行时 python 显示以下错误。

Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/tkinter/__init__.py", line 1885, in __call__
    return self.func(*args)
  File ".../expts/test.py", line 20, in callback
    text.insert("1.0", "howdy")
  File ".../expts/test.py", line 14, in new_insert
    tk.Text.insert(text, index, chars, *args)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/tkinter/__init__.py", line 3740, in insert
    self.tk.call((self._w, 'insert', index, chars) + args)
AttributeError: type object 'Text' has no attribute 'tk'

以下代码是我的主要代码的简化版本。

import tkinter as tk
import types

class TextChild(tk.Text):
    def __init__(self, *args, **kwargs):
        tk.Text.__init__(self, *args, **kwargs)

root = tk.Tk()
text = TextChild(root)
text.pack()

def new_insert(text, index, chars, *args):
    print("Does some work...")
    tk.Text.insert(text, index, chars, *args)

text.insert = types.MethodType(new_insert, tk.Text)

def callback():
    global text
    text.insert("1.0", "howdy")

button = tk.Button(master=root,text="Button", command=callback)
button.pack()

root.mainloop()
4

2 回答 2

3

在继承的类中更容易做到这一点：

class TextChild(tk.Text):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

    def insert(self, index, chars, *args):
        print("Does some work ...")
        # call original insert()
        super().insert(index, chars, *args)
于 2021-01-27T02:15:24.573 回答
1

为了解决您的原始方法，您正在混淆types.MethodType. 参数是方法和对象。

text.insert = types.MethodType(new_insert, text)
于 2021-01-27T02:19:03.877 回答