Tkinter命令Lambda函数修改变量 [英] Tkinter Command Lambda Function Modify Variable

问题描述

我的应用程序是一种从数据库填充其字段的表单.我正在编写在这些记录之间导航的函数.我在编写下一条记录"功能时遇到问题.

My application is a form which populates its fields from a database. I am in the process of writing the function that navigates between these records. I am having problems writing my "next record" function.

在任何给定时间，屏幕上显示的当前记录"都在变量 current_record 中.

At any given time, the "Current Record" showing on the screen is in a variable current_record.

def next_record(current_record):
    current_index = current_record.index
    current_record = Competitor(competitors[current_index + 1], current_index + 1)
    print(current_record.index)
    populate_form(current_record)

然后我的按钮调用此函数:

And my button calling this function:

action_button_6 = tkinter.Button(group_buttons, text='>>', width=5,
                                 command=lambda: next_record(current_record))

尽管该功能完成了工作并将新记录加载到表单中，但并未如功能第三行所示将"current_record"重新分配给新竞争对手.

Although the function does its job and loads the new record into the form, it does not reassign "current_record" to the new competitor as show in the third line of the function.

如何在此函数中修改变量?

How can I modify the variable from within this function?

推荐答案

除非您明确声明在全局函数中修改的变量，否则即使存在具有相同名称的全局变量，因此 current_record 是局部变量.将 global current_record 添加到 next_record 函数的开头，并将函数参数重命名为 old_record 即可解决此问题.

Unless you explicitly declare a variable that you modify in a function global, it defaults to being local even if there is a global variable with the same name, thus current_record is a local variable. Adding global current_record to the beginning of the next_record function and renaming the function argument to old_record would fix that.

这篇关于Tkinter命令Lambda函数修改变量的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！