游戏导入矩形的玩法问题

Question

我有一个关于在游戏中放置长方形的小问题。当我运行代码时，我看不到矩形。有人知道怎么解决这个问题吗？

import pygame as pg
from pygame.locals import *

pg.init()

BLACK = ( 0, 0, 0)
WHITE = ( 255, 255, 255)
GREEN = ( 0, 255, 0)
RED = ( 255, 0, 0)


size = width, height = (800, 800)
screen = pg.display.set_mode(size)
pg.display.set_caption("Ball Game")
screen.fill((10, 255, 255))
pg.display.update()
running = True
clock = pg.time.Clock()

#board = pg.draw.rect(screen, BLACK, pg.Rect(30, 30, 60, 60))
#board_loc = pg.
#board_loc.center = width/2, height*0.8

background_image = pg.image.load("pngtree-blue-cartoon-minimalist-planet-surface-starry-sky-main-map-background-image_186868.jpg").convert()

while running:
    for event in pg.event.get():
        if event.type == QUIT:
            running = False
    screen.blit(background_image, [0, 0])
    pg.display.flip()
    #screen.blit(board, board_loc)
    rect = pg.Rect(0, 0, 200, 100)
    rect.center = (300, 300)
    pg.draw.rect(screen, BLACK, rect)


clock.tick(30)
pg.quit()

在这里输入图像描述

Answer 1

绘制矩形后，必须更新显示：

rect = pg.Rect(0, 0, 200, 100)
rect.center = (300, 300)

while running:
    for event in pg.event.get():
        if event.type == QUIT:
            running = False

    # draw background
    screen.blit(background_image, [0, 0])
   
    # draw rectangle on top of the background 
    pg.draw.rect(screen, BLACK, rect)

    # update display
    pg.display.flip()

您实际上是在Surface对象上绘图。如果在与PyGame显示相关联的曲面上绘图，这在显示中不会立即可见。当使用pygame.display.update()或pygame.display.flip()更新显示时，更改将变得可见。