如何让Pygame程序首次生成随机数字后停止持续刷新更新

你的随机数生成逻辑写在了start_the_game()函数内部，而这个函数在主while循环里每帧都会被调用一次，所以每次循环都会重新生成新的x、y值，导致数字持续刷新。

你猜想的用if语句控制是可行的，这里提供两种修改方案：

方案1：调整变量作用域（更推荐） #

把只需要生成一次的随机数、题目文本放到主循环外初始化，主循环内只做界面渲染和事件处理即可：

import pygame
import random

pygame.init()

clock = pygame.time.Clock()
surface = pygame.display.set_mode((600, 400))
pygame.display.set_caption("Projecte MatZanfe")
font = pygame.font.SysFont('comicsans', 50)
base_font = pygame.font.Font(None, 32)
user_text = ''
color_active = pygame.Color('lightskyblue3')

# 把只需要生成一次的内容移到循环外
is_correct = False
points = 0
x = random.randint(0,10)
y = random.randint(0,10)
z = x + y
# 题目文本也只需要渲染一次
question_text = font.render (str(x) + "+" + str(y), True, (255,255,255))
input_rect = pygame.Rect(200,200,180,50)

def render_game():
    surface.fill((255,70,90))
    pygame.draw.rect(surface,color_active,input_rect)
    text_surface = base_font.render(user_text,True,(255,255,255))
    # 修正了原代码文字贴输入框边框的问题
    surface.blit(text_surface, (input_rect.x+5, input_rect.y+5))
    surface.blit(question_text,(260,120))
    input_rect.w = max(100,text_surface.get_width()+10)

running = True
while running:
    clock.tick(60)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        # 补充原代码缺失的键盘输入处理逻辑
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_BACKSPACE:
                user_text = user_text[:-1]
            elif event.key == pygame.K_RETURN:
                # 可在此处添加答案校验、切换下一题的逻辑
                if user_text.isdigit() and int(user_text) == z:
                    print("回答正确")
                    user_text = ''
            else:
                if event.unicode.isdigit():
                    user_text += event.unicode
    render_game()
    pygame.display.update()
pygame.quit()

方案2：用if状态标记控制（符合你预期的if语句实现思路） #

如果不想调整原有代码结构，可以加一个标记位控制随机数是否已经生成：

import pygame
import random

pygame.init()

clock = pygame.time.Clock()
surface = pygame.display.set_mode((600, 400))
pygame.display.set_caption("Projecte MatZanfe")
font = pygame.font.SysFont('comicsans', 50)
base_font = pygame.font.Font(None, 32)
user_text = ''
color_active = pygame.Color('lightskyblue3')

# 新增标记位，判断是否已经生成过随机数
num_generated = False
x = 0
y = 0
z = 0
question_text = None

def start_the_game():
    global num_generated, x, y, z, question_text
    is_correct = False
    points = 0
    # 仅未生成过随机数时执行生成逻辑
    if not num_generated:
        x = random.randint(0,10)
        y = random.randint(0,10)
        z = x + y
        question_text = font.render (str(x) + "+" + str(y), True, (255,255,255))
        num_generated = True
    surface.fill((255,70,90))
    input_rect = pygame.Rect(200,200,180,50)

    pygame.draw.rect(surface,color_active,input_rect)
    text_surface = base_font.render(user_text,True,(255,255,255))
    surface.blit(text_surface, (input_rect.x+5, input_rect.y+5))
    surface.blit(question_text,(260,120))
    input_rect.w = max(100,text_surface.get_width()+10)

running = True
while running:
    clock.tick(60)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        # 补充键盘输入逻辑
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_BACKSPACE:
                user_text = user_text[:-1]
            elif event.unicode.isdigit():
                user_text += event.unicode
    start_the_game()
    pygame.display.update()
pygame.quit()

内容的提问来源于stack exchange，提问作者Torchllama