button.Button 类错误:'button_list 未定义'..... :( 使用 replit [英] button.Button class error:'button_list not defined'..... :( using replit

问题描述

我正在学习为平台游戏创建地图编辑器的在线教程，但我的导入按钮功能不起作用，显示错误button_list 未定义"，但我不明白这是为什么，因为我已经将其定义为空列表?我有按钮类的以下代码.

I am following a tutorial online creating a map editor for a platform game and my import button feature is not working, showing error 'button_list not defined' but I can not see why this is as I defined it as empty list already? I have the following code for the button class.

import pygame
import button

def button():
    button_list = []
    button_col = 0
    button_row = 0
    for i in range(len(img_list)):
        tile_button = button.Button(SCREEN_WIDTH + (75 * button_col) + 50, 75 * button_row + 50, img_list[i], 1)
        button_list.append(tile_button)
        button_col += 1
        if button_col == 3:
            button_row += 1
            button_col = 0

这没有错误并且运行正常，(当然屏幕上没有任何内容)但是当我使用以下代码绘制它时发生错误......请帮忙！

This has no errors and runs OK, (nothing on screen of course) but when I draw it with the following code the error occurs.... please help!

for i in button_list:
    i.draw(screen)

推荐答案

你必须使用 global 语句 如果你想在函数内的全局命名空间中定义一个变量:

You have to use the global statement if you want to define a variable in the global namespace within a function:

def button():
    global button_list 

    button_list = []

    button_col = 0
    button_row = 0
    for i in range(len(img_list)):
        # [...]

button()
for i in button_list:
    i.draw(screen)

---

或者，您可以在全局命名空间中定义 button_list:

button_list = []

def button():
    button_col = 0
    button_row = 0
    for i in range(len(img_list)):
        tile_button = button.Button(SCREEN_WIDTH + (75 * button_col) + 50, 75 * button_row + 50, img_list[i], 1)
        button_list.append(tile_button)
        button_col += 1
        if button_col == 3:
            button_row += 1
            button_col = 0

这篇关于button.Button 类错误:'button_list 未定义'..... :( 使用 replit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！