>我有一个代码解决了这个问题 在pygame中执行for循环后，图像不会保留在屏幕上。所以我决定根据我从pygame学到的东西来放置一些平台。我还决定让牛仔向左右移动，然后向下移动到屏幕底部。
但是，如图所示，当牛仔的右侧或左侧发生碰撞时，class PlayerShip在通过def draw_reaction ()函数的主循环中没有按预期执行，因为我没有看到player_sprite所代表的牛仔图像固定在位置(60, 48)。只有当牛仔从下面被击中时，它才能正常工作。
资产
导弹.png
牛仔.png
警察.png
图：
|missile| <--<-- (is touched its right side by the missile)|cowboy| <--<-- direction
^
|
^
|
(fire missile direction vertical)
^
|
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我的 MWE 编码：
import pygame
import random
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
BLUE = (0, 0, 255)
GREEN = (0, 255, 0)
RED = (255, 0, 0)
PURPLE = (255, 0, 255)
GRAY = (128,128,128)
SCREEN_WIDTH = 800
SCREEN_HEIGHT = 600
class PlayerShip( pygame.sprite.Sprite ):
def __init__(self):
super().__init__()
self.image = pygame.image.load( "cowboy.png" )
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
self.rect.topleft = ( 60, 48 )
player_sprite = PlayerShip()
class Platform(pygame.sprite.Sprite):
def __init__(self, width, height):
super().__init__()
self.image = pygame.Surface([width, height])
self.image.fill(GREEN)
self.rect = self.image.get_rect()
class MovingPlatform(Platform):
change_x = 0
change_y = 0
boundary_top = 0
boundary_bottom = 0
boundary_left = 0
boundary_right = 0
player = None
level = None
def update(self):
self.rect.x += self.change_x
hit = pygame.sprite.collide_rect(self, self.player)
if hit:
if self.change_x < 0:
self.player.rect.right = self.rect.left
else:
self.player.rect.left = self.rect.right
self.rect.y += self.change_y
hit = pygame.sprite.collide_rect(self, self.player)
if hit:
if self.change_y < 0:
self.player.rect.bottom = self.rect.top
else:
self.player.rect.top = self.rect.bottom
if self.rect.bottom > self.boundary_bottom or self.rect.top < self.boundary_top:
self.change_y *= -1
cur_pos = self.rect.x - self.level.world_shift
if cur_pos < self.boundary_left or cur_pos > self.boundary_right:
self.change_x *= -1
class Level(object):
def __init__(self, player):
self.platform_list = pygame.sprite.Group()
self.enemy_list = pygame.sprite.Group()
self.player = player
self.background = None
self.world_shift = 0
self.level_limit = -1000
def update(self):
self.platform_list.update()
self.enemy_list.update()
def draw(self, screen):
screen.fill(GRAY)
self.platform_list.draw(screen)
self.enemy_list.draw(screen)
def shift_world(self, shift_x):
self.world_shift += shift_x
for platform in self.platform_list:
platform.rect.x += shift_x
for enemy in self.enemy_list:
enemy.rect.x += shift_x
class Room(object):
wall_list = None
enemy_sprites = None
def __init__(self):
self.wall_list = pygame.sprite.Group()
self.enemy_sprites = pygame.sprite.Group()
class Level_01(Level):
def __init__(self, player):
Level.__init__(self, player)
self.level_limit = -1500
level = [[210, 70, 500, 500],
[210, 70, 800, 400],
[210, 70, 1000, 500],
[210, 70, 1120, 280],
[210, 70, -120, 500],
]
for platform in level:
block = Platform(platform[0], platform[1])
block.rect.x = platform[2]
block.rect.y = platform[3]
block.player = self.player
self.platform_list.add(block)
block = MovingPlatform(70, 40)
block.rect.x = 1350
block.rect.y = 280
block.boundary_left = 1350
block.boundary_right = 1600
block.change_x = 10
block.player = self.player
block.level = self
self.platform_list.add(block)
class Level_02(Level):
def __init__(self, player):
Level.__init__(self, player)
self.level_limit = -1000
level = [[210, 70, 500, 550],
[210, 70, 800, 400],
[210, 70, 1000, 500],
[210, 70, 1120, 280],
]
for platform in level:
block = Platform(platform[0], platform[1])
block.rect.x = platform[2]
block.rect.y = platform[3]
block.player = self.player
self.platform_list.add(block)
block = MovingPlatform(70, 70)
block.rect.x = 1500
block.rect.y = 300
block.boundary_top = 100
block.boundary_bottom = 550
block.change_y = -1
block.player = self.player
block.level = self
self.platform_list.add(block)
class Player(pygame.sprite.Sprite):
def __init__(self):
super().__init__()
width = 40
height = 60
self.image = pygame.image.load("police.png").convert()
self.rect = self.image.get_rect()
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
self.change_x = 0
self.change_y = 0
self.level = None
def update(self):
self.calc_grav()
self.rect.x += self.change_x
block_hit_list = pygame.sprite.spritecollide(self, self.level.platform_list, False)
for block in block_hit_list:
if self.change_x > 0:
self.rect.right = block.rect.left
elif self.change_x < 0:
self.rect.left = block.rect.right
self.change_y += 0
self.rect.y += self.change_y
block_hit_list = pygame.sprite.spritecollide(self, self.level.platform_list, False)
for block in block_hit_list:
if self.change_y > 0:
self.rect.bottom = block.rect.top
elif self.change_y < 0:
self.rect.top = block.rect.bottom
self.change_y = 0
if isinstance(block, MovingPlatform):
self.rect.x += block.change_x
def calc_grav(self):
if self.change_y == 0:
self.change_y = 1
else:
self.change_y += .35
if self.rect.y >= SCREEN_HEIGHT - self.rect.height and self.change_y >= 0:
self.change_y = 0
self.rect.y = SCREEN_HEIGHT - self.rect.height
def jump(self):
self.rect.y += 2
platform_hit_list = pygame.sprite.spritecollide(self, self.level.platform_list, False)
self.rect.y -= 2
if len(platform_hit_list) > 0 or self.rect.bottom >= SCREEN_HEIGHT:
self.change_y = -10
def go_left(self):
self.change_x = -6
def go_right(self):
self.change_x = 6
def stop(self):
self.change_x = 0
class Cowboy(pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.image = pygame.image.load("cowboy.png").convert()
self.rect = self.image.get_rect()
self.image.set_colorkey(BLACK)
class Missile(pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.image = pygame.image.load("missile.png").convert()
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
def update(self):
self.rect.y += -3
def main():
pygame.init()
size = [SCREEN_WIDTH, SCREEN_HEIGHT]
screen = pygame.display.set_mode(size)
block_list = pygame.sprite.Group()
all_sprites_list = pygame.sprite.Group()
bullet_list = pygame.sprite.Group()
pygame.display.set_caption("Platformer with moving platforms")
apple = pygame.image.load("missile.png").convert()
block = Cowboy()
player_image = pygame.image.load("cowboy.png").convert()
player = Player()
level_list = []
level_list.append(Level_01(player))
level_list.append(Level_02(player))
current_level_no = 0
current_level = level_list[current_level_no]
block_list.add(block)
all_sprites_list.add(block)
all_sprites_list.add(player)
active_sprite_list = pygame.sprite.Group()
player.level = current_level
player.rect.x = 340
player.rect.y = SCREEN_HEIGHT - player.rect.height
active_sprite_list.add(player)
done = False
clock = pygame.time.Clock()
x_speed = 0
y_speed = 0
rect_x = 50
rect_y = 50
rect_change_x = 1
rect_change_y = 90
x = rect_x
y = rect_y
player.rect.y = rect_x
player.rect.y = 480
score = 0
size = (1366, 768)
screen = pygame.display.set_mode(size, pygame.RESIZABLE)
while not done:
x += x_speed
y += y_speed
rect_x += rect_change_x
if rect_x > 280:
rect_change_x *= -1
rect_x += rect_change_x
rect_y += rect_change_y
if rect_x < 0:
rect_change_x *= -1
rect_x += rect_change_x
rect_y += rect_change_y
block.rect.x = rect_x
block.rect.y = rect_y
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
elif event.type == pygame.MOUSEBUTTONDOWN:
bullet = Missile()
bullet.rect.x = player.rect.x
bullet.rect.y = player.rect.y
all_sprites_list.add(bullet)
bullet_list.add(bullet)
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_LEFT:
player.go_left()
if event.key == pygame.K_RIGHT:
player.go_right()
if event.key == pygame.K_UP:
player.jump()
if event.type == pygame.KEYUP:
if event.key == pygame.K_LEFT and player.change_x < 0:
player.stop()
if event.key == pygame.K_RIGHT and player.change_x > 0:
player.stop()
for bullet in bullet_list:
block_hit_list = pygame.sprite.spritecollide(bullet, block_list, True)
for block in block_hit_list:
bullet_list.remove(bullet)
all_sprites_list.remove(bullet)
score += 1
print(score)
screen.blit(player_image, [60, 48])
if bullet.rect.y < -10:
bullet_list.remove(bullet)
all_sprites_list.remove(bullet)
def draw_reaction():
for bullet in bullet_list:
block_hit_list = pygame.sprite.spritecollide(bullet, block_list, True)
for block in block_hit_list:
all_sprites_list.add( player_sprite )
break
all_sprites_list.update()
active_sprite_list.update()
current_level.update()
if player.rect.right >= 1500:
diff = player.rect.right - 500
player.rect.right = 500
current_level.shift_world(-diff)
if player.rect.left <= 120:
diff = 120 - player.rect.left
player.rect.left = 120
current_level.shift_world(diff)
current_position = player.rect.x + current_level.world_shift
if current_position < current_level.level_limit:
if current_level_no < len(level_list)-1:
player.rect.x = 120
current_level_no += 1
current_level = level_list[current_level_no]
player.level = current_level
else:
done = True
current_level.draw(screen)
active_sprite_list.draw(screen)
x += x_speed
y += y_speed
all_sprites_list.draw(screen)
draw_reaction()
clock.tick(60)
pygame.display.flip()
pygame.quit()
if __name__ == "__main__":
main()
更新编辑：如果主循环中未使用current_level.draw(screen)则代码按预期工作。但我仍然不知道是什么原因造成的。
我只是在for block in block_hit_list:中添加了all_sprites_list.add (player_sprite)。在我看来，这对于跟踪self.image.get_rect ()是必要的。 然后：
以前：
for bullet in bullet_list:
block_hit_list = pygame.sprite.spritecollide(bullet, block_list, True)
for block in block_hit_list:
bullet_list.remove(bullet)
all_sprites_list.remove(bullet)
score += 1
print(score)
screen.blit(player_image, [60, 48])
if bullet.rect.y < -10:
bullet_list.remove(bullet)
all_sprites_list.remove(bullet)
后：
for bullet in bullet_list:
block_hit_list = pygame.sprite.spritecollide(bullet, block_list, True)
for block in block_hit_list:
all_sprites_list.add(player_sprite)
bullet_list.remove(bullet)
all_sprites_list.remove(bullet)
score += 1
print(score)
screen.blit(player_image, [60, 48])
if bullet.rect.y < -10:
bullet_list.remove(bullet)
all_sprites_list.remove(bullet)
但我希望有人通过对文档或代码本身的样式进行更有经验的引用，向我解释代码背后的真实情况。如果有人能做出这样的解释，非常感谢。