如何在函数内部时从 tkinter 文本小部件获取输入

Question

相对较新的编码，目前我在 python 中使用 tkinter，我在函数中使用文本小部件，并希望将输入从文本框发送到另一个函数。我的全局变量在模块级别未定义，那么如果它在函数内，我怎么能在模块级别定义它？

当我按下发送电子邮件按钮时，我收到此错误消息 “NameError: name 'user_message_entry' is not defined”

有什么建议吗？非常感谢！

最小复制：

import tkinter as tk

root = tk.Tk()
root.geometry("500x500")


def send_email():
    global user_message_entry
    subject = ":)"
    body = user_message_entry.get("1.0", "end")
    message = f"subject: {subject}\n\n {body}"
    print(message)


def feedback():
    feedback_window = tk.Toplevel()
    feedback_window.geometry("690x650")

    message_frame = tk.Frame(feedback_window)
    message_frame.grid(row=0, column=0, columnspan=3)
    user_message_entry = tk.Text(message_frame, height=10, width=60)
    user_message_entry.grid(row=0, column=0)

    send_email_button = tk.Button(feedback_window, command=send_email,
                                  height=20, width=20, bg="yellow", text="send email")
    send_email_button.grid(row=1, column=0)


open_feedback_button = tk.Button(root, command=feedback, height=20, width=20, bg="yellow", text="open feedback window")
open_feedback_button.grid(row=1, column=0)

root.mainloop()

Answer 1

您可以使用面向对象的方法来使访问更简单，另一种选择也可以使用 globals() 来使变量全局化

一种方式

globals()['user_message_entry'] = tk.Text(message_frame, height=10, width=60)

.... 

你可以从另一个函数调用

body = globals()['user_message_entry'].get("1.0", "end")

第二种方式

面向对象的编程适用于各种类型的问题解决，所以你也可以使用类

import tkinter as tk

class CBased:
    def __init__(self, master, *args, **kwargs):
        super(CBased, self).__init__(*args, *kwargs)
        self.master = master
        master.geometry("500x500")

        self.open_feedback_button = tk.Button(master, command=self.feedback, height=20, width=20, bg="yellow", text="open feedback window")
        self.open_feedback_button.grid(row=1, column=0)

    def send_email(self):
        subject = ":)"
        body = self.user_message_entry.get("1.0", "end")
        message = f"subject: {subject}\n\n {body}"
        print(message)


    def feedback(self):
        self.feedback_window = tk.Toplevel()
        self.feedback_window.geometry("690x650")

        self.message_frame = tk.Frame(self.feedback_window)
        self.message_frame.grid(row=0, column=0, columnspan=3)
        self.user_message_entry = tk.Text(self.message_frame, height=10, width=60)
        self.user_message_entry.grid(row=0, column=0)

        self.send_email_button = tk.Button(self.feedback_window, command=send_email,
                                  height=20, width=20, bg="yellow", text="send email")
        self.send_email_button.grid(row=1, column=0)

def main():
    root        = Tk()
    myobj       = CBased(root)
    root.mainloop()

if __name__ == "__main__":main()

这样你就可以通过self.xyz调用每一个项目