清洁条目小部件

Question

我从谷歌翻译的，对语法很抱歉。我正在学习自己编程，需要一些帮助。我想通过单击按钮来清理条目小部件。问题是我不知道如何绑定“class MainWindow”类中的命令。

import tkinter as tk
from tkinter import ttk

class InserFrame(ttk.Frame):
    def __init__(self):
        super().__init__()
        self.__create_widget()
    def __create_widget(self):
        ttk.Label(self, text="Label1").grid(row=0, column=0, sticky=tk.W)
        keyword1 = ttk.Entry(self)
        keyword1.focus()
        keyword1.grid(row=0, column=1, sticky=tk.W)
        ttk.Label(self, text="Label2").grid(row=1, column=0, sticky=tk.W)
        keyword2 = ttk.Entry(self)
        keyword2.grid(row=1, column=1, sticky=tk.W)
        ttk.Label(self, text="Label3").grid(row=2, column=0, sticky=tk.W)
        keyword3 = ttk.Entry(self)
        keyword3.grid(row=2, column=1, sticky=tk.W)
        ttk.Label(self, text="Label4").grid(row=3, column=0, sticky=tk.W)
        keyword4 = ttk.Entry(self)
        keyword4.grid(row=3, column=1, sticky=tk.W)

        for widgets in self.winfo_children():
            widgets.grid(pady=7)

class ButtonFrame(ttk.Frame):
    def __init__(self):
        super().__init__()
        self.__create_widget()
    def __create_widget(self):
        ttk.Button(self, text="Button1").grid(row=0, column=0)
        ttk.Button(self, text="Button2").grid(row=1, column=0)
        ttk.Button(self, text="Button3").grid(row=2, column=0)
        ttk.Button(self, text="Button4").grid(row=3, column=0)
        for widget in self.winfo_children():
            widget.grid(pady=5)
        

class MainWindow(tk.Tk):
    def __init__(self):
        super().__init__()
        self.geometry("400x400")
        self.title("Prova")
        self.columnconfigure(0, weight=4)
        self.columnconfigure(1, weight=1)
        self.__create_widgets()
  this--------->      ttk.Button(self, text="Clear").grid(row=4, column=0, sticky="E")
    def __create_widgets(self):
        insert_frame = InserFrame()
        insert_frame.grid(row=0, column=0, sticky=tk.W)
        insert_button = ButtonFrame()
        insert_button.grid(row=0, column=1, sticky=tk.E)
        for widget in self.winfo_children():
            widget.grid(padx=5, pady=5)

if __name__=="__main__":
    main_window = MainWindow()
    main_window.mainloop()`

Answer 1

您可以在构造 Button 对象时将回调函数分配给

command

参数。

def button_callback():
   # Your clearing code here.
   ...

ttk.Button(self, text="Clear", command=button_callback)

Answer 2

我不知道当您可以直接在

__init__

函数中创建框架元素时，您是否有特定原因通过函数创建它们。这样它们就可以直接分配给实例变量。

但是，您可以为

MainWindow

类创建一个函数来删除条目的内容，并将此函数分配给

command

按钮的

"Clear"

属性：

import tkinter as tk
from tkinter import ttk, END


class InserFrame(ttk.Frame):
    def __init__(self):
        super().__init__()
        # assign entries to instance variables to be accessed through frame instance
        self.k1, self.k2, self.k3, self.k4 = self.__create_widget()

    def __create_widget(self):
        ttk.Label(self, text="Label1").grid(row=0, column=0, sticky=tk.W)
        keyword1 = ttk.Entry(self)
        keyword1.focus()
        keyword1.grid(row=0, column=1, sticky=tk.W)
        ttk.Label(self, text="Label2").grid(row=1, column=0, sticky=tk.W)
        keyword2 = ttk.Entry(self)
        keyword2.grid(row=1, column=1, sticky=tk.W)
        ttk.Label(self, text="Label3").grid(row=2, column=0, sticky=tk.W)
        keyword3 = ttk.Entry(self)
        keyword3.grid(row=2, column=1, sticky=tk.W)
        ttk.Label(self, text="Label4").grid(row=3, column=0, sticky=tk.W)
        keyword4 = ttk.Entry(self)
        keyword4.grid(row=3, column=1, sticky=tk.W)

        for widgets in self.winfo_children():
            widgets.grid(pady=7)

        # return entries to access them
        return keyword1, keyword2, keyword3, keyword4


class ButtonFrame(ttk.Frame):
    def __init__(self):
        super().__init__()
        self.__create_widget()

    def __create_widget(self):
        ttk.Button(self, text="Button1").grid(row=0, column=0)
        ttk.Button(self, text="Button2").grid(row=1, column=0)
        ttk.Button(self, text="Button3").grid(row=2, column=0)
        ttk.Button(self, text="Button4").grid(row=3, column=0)
        for widget in self.winfo_children():
            widget.grid(pady=5)


class MainWindow(tk.Tk):
    def __init__(self):
        super().__init__()
        self.geometry("400x400")
        self.title("Prova")
        self.columnconfigure(0, weight=4)
        self.columnconfigure(1, weight=1)
        # assign created frame to instance variable
        self.insert_frame = self.__create_widgets()
        # give command argument to button with function to clear contents
        ttk.Button(self, text="Clear", command=self.clear_inputs).grid(row=4, column=0, sticky="E")

    def __create_widgets(self):
        insert_frame = InserFrame()
        insert_frame.grid(row=0, column=0, sticky=tk.W)
        insert_button = ButtonFrame()
        insert_button.grid(row=0, column=1, sticky=tk.E)
        for widget in self.winfo_children():
            widget.grid(padx=5, pady=5)
        # retrun created frame to access it
        return insert_frame

    # function to clear the entries
    def clear_inputs(self):
        self.insert_frame.k1.delete(0, END)
        self.insert_frame.k2.delete(0, END)
        self.insert_frame.k3.delete(0, END)
        self.insert_frame.k4.delete(0, END)


if __name__ == "__main__":
    main_window = MainWindow()
    main_window.mainloop()