Python - Pygame不在按钮上显示文本

import pygame
import sys

BUTTON_COLOR = (255, 255, 255)  # 按钮颜色为白色
BUTTON_WIDTH = 200  # 按钮宽度为200像素
BUTTON_HEIGHT = 50  # 按钮高度为50像素

def draw_button(screen, x, y, width, height, color, text):
    pygame.draw.rect(screen, color, (x, y, width, height))  # 绘制按钮矩形
    font = pygame.font.Font(None, 36)  # 设置文本字体和大小
    text_surface = font.render(text, True, (0, 0, 0))  # 渲染文本
    text_rect = text_surface.get_rect()
    text_rect.center = (x + width / 2, y + height / 2)  # 设置文本位置居中
    screen.blit(text_surface, text_rect)  # 绘制文本

pygame.init()
screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Button Example")

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()

    screen.fill((0, 0, 0))  # 清空屏幕

    # 绘制按钮和文本
    draw_button(screen, 300, 250, BUTTON_WIDTH, BUTTON_HEIGHT, BUTTON_COLOR, "Click Me")

    pygame.display.flip()  # 更新屏幕显示