射击问题:如何在射击前展示子弹

Question

我希望在空格键按下时显示"香蕉"，同时它跟随角色的移动，然后在释放时激发它

import pygame
from pygame.locals import *


#inizializzazione
pygame.init()
screen=pygame.display.set_mode((400,750))
pygame.display.set_caption('MonkeyBanana')
FPS=60



#load image
img_ground = pygame.image.load('Surf/sfondo.jpg').convert_alpha()
surf_ground=pygame.transform.scale(img_ground,(img_ground.get_width(),screen.get_height()))


class Monkey (pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.sprites = [pygame.transform.scale((pygame.image.load('Surf/Animazioni/monkey_idle_00.png').convert_alpha()),
(screen.get_width() / 5, screen.get_height() / 7)),
pygame.transform.scale((pygame.image.load('Surf/Animazioni/monkey_idle_01.png').convert_alpha()),
(screen.get_width() / 5, screen.get_height() / 7)),
pygame.transform.scale((pygame.image.load('Surf/Animazioni/monkey_idle_02.png').convert_alpha()),
(screen.get_width() / 5, screen.get_height() / 7)),
pygame.transform.scale((pygame.image.load('Surf/Animazioni/monkey_idle_03.png').convert_alpha()),
(screen.get_width() / 5, screen.get_height() / 7))
]

self.launch_monkey=[]
for i in range(0, 19):
filename = "Surf/Animazioni/monkey_{:0>3}.png".format(i)
img = pygame.image.load(filename).convert_alpha()
img_reduced = pygame.transform.scale(img, (screen.get_width() / 5, screen.get_height() / 7))
self.launch_monkey.append(img_reduced)

self.count=0
self.count1 = 0


self.image = self.sprites[self.count]
self.rect = self.image.get_rect()
self.rect.midbottom = (screen.get_width() / 2, screen.get_height())
all_sprites.add(self)

def update(self):
self.count += 0.08
if self.count >= 3:
self.count = 0
self.image = self.sprites[int(self.count)]
if move_right and monkey.rect.right < screen.get_width():
monkey.rect.x += 5
elif move_left and monkey.rect.left > 0:
monkey.rect.x -= 5

def launch(self):
global launch

if launch:
self.count1 += 1
if self.count1 >= 19:
self.count1 = 0
launch = False
self.image = self.launch_monkey[int(self.count1)]


class Banana (pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.image= pygame.transform.scale((pygame.image.load('Surf/banana.png').convert_alpha()),
(screen.get_width() / 10, screen.get_height() / 15))
self.rect=self.image.get_rect()
self.rect.center = monkey.rect.center
all_banana.add(self)

问题出在这里首次发布时一切正常。第二次按下空格键时，香蕉会回到角色手中，而不是继续运行。

def update(self):
global new_banana
if keep_banana:
self.rect.center = monkey.rect.center
new_banana=False

if launch_banana:
self.rect.y -= 5

if self.rect.top<50:
self.kill()


#create sprite and Group

all_sprites = pygame.sprite.Group()
all_banana= pygame.sprite.Group()
monkey=Monkey()


#other variables
move_right=False
move_left=False
launch=False
launch_banana=False
keep_banana=False
new_banana=False



#principal cicle
done=False
while not done:

for ev in pygame.event.get():
if ev.type == QUIT:
done = True
if ev.type ==KEYDOWN:
if ev.key== K_RIGHT:
move_right=True
idle = False
if ev.key== K_LEFT:
move_left = True
idle = False
if ev.key==K_SPACE:
keep_banana = True
new_banana=True

elif ev.type ==KEYUP:
if ev.key== K_RIGHT:
move_right=False
idle = True
if ev.key== K_LEFT:
move_left=False
idle = True
if ev.key==K_SPACE:
launch_banana=True
keep_banana = False
launch = True

#Game logic
if new_banana:
banana=Banana()

#screen update


screen.blit(surf_ground, (0, 0))
all_sprites.draw(screen)
all_banana.draw(screen)
all_banana.update()
all_sprites.update()
monkey.launch()
pygame.display.flip()
pygame.time.Clock().tick(FPS)

#end principal cicle
pygame.quit()

它在另一个没有类的版本中对我有效，每次它被解雇时都会将香蕉添加到一个新的组中，但我无法让它在类上工作。我试了很多次，但似乎都不起作用

Answer 1

launch_banana让香蕉飞起来：

if launch_banana:
self.rect.y -= 5

launch_banana一开始是False，但一旦它变成True，就再也不会设置False。当keep_banana设置为True:时，必须将launch_banana设置为False

launch_banana=False
keep_banana=False
new_banana=False
# [...]
while not done:
for ev in pygame.event.get():
# [...]
if ev.type == KEYDOWN:
# [...]
if ev.key == K_SPACE:
launch_banana = False        # <---
keep_banana = True
new_banana = True
elif ev.type == KEYUP:
# [...]
if ev.key == K_SPACE:
launch_banana = True
keep_banana = False
launch = True

---

无论如何，我建议在Banana类中添加一个状态，而不是所有这些布尔变量。该状态可以是"；保持"；在开始时可以被改变为"0"；启动"；香蕉启动后。

class Banana (pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.image= pygame.transform.scale((pygame.image.load('Surf/banana.png').convert_alpha()),
(screen.get_width() / 10, screen.get_height() / 15))
self.rect=self.image.get_rect()
self.rect.center = monkey.rect.center
all_banana.add(self)
self.state = "keep"
def start(self):
self.state = "launched"
def update(self):
if self.state == "keep":
self.rect.center = monkey.rect.center

elif self.state == "launched":
self.rect.y -= 5

if self.rect.top<50:
self.kill()

Answer 2

感谢的回复

所以

在Space中实现launch_banana=False Keydown不起作用：

if ev.key == K_SPACE:
launch_banana = False        # <---
keep_banana = True
new_banana = True

我在游戏逻辑中以这种方式实现了香蕉状态，并通过创建2个精灵组来很好地工作：

import pygame
from pygame.locals import *

#inizializzazione
pygame.init()
screen=pygame.display.set_mode((400,750))
pygame.display.set_caption('MonkeyBanana')
FPS=60

#load image
img_ground = pygame.image.load('Surf/sfondo.jpg').convert_alpha()
surf_ground=pygame.transform.scale(img_ground,(img_ground.get_width(),screen.get_height()))

class Monkey (pygame.sprite.Sprite):
[...]
class Banana(pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.image = pygame.transform.scale((pygame.image.load('Surf/banana.png').convert_alpha()),
(screen.get_width() / 10, screen.get_height() / 15))
self.rect = self.image.get_rect()
self.rect.center = monkey.rect.center
one_banana.add(self)   <-------------GroupSingle
self.state = "keep"

def start(self):
self.state = "launched"
def update(self):
if self.state == "keep":
self.rect.center = monkey.rect.center
elif self.state == "launched":
self.rect.y -= 5
if self.rect.top < 50:
self.kill()

#create sprite and Group
all_sprites = pygame.sprite.Group()
all_banana= pygame.sprite.Group()
one_banana= pygame.sprite.GroupSingle() <------add this group
monkey=Monkey()

#other variables
move_right=False
move_left=False
launch=False
launch_banana=False
keep_banana=False
new_banana=False

#principal cicle
done=False
while not done:
for ev in pygame.event.get():
if ev.type == QUIT:
done = True
if ev.type ==KEYDOWN:
if ev.key== K_RIGHT:
move_right=True
idle = False
if ev.key== K_LEFT:
move_left = True
idle = False
if ev.key==K_SPACE:
keep_banana = True
new_banana=True
elif ev.type ==KEYUP:
if ev.key== K_RIGHT:
move_right=False
idle = True
if ev.key== K_LEFT:
move_left=False
idle = True
if ev.key==K_SPACE:
launch_banana=True
keep_banana = False
launch = True
#Game logic
**if new_banana:
banana=Banana()
if launch_banana:
one_banana.empty()
all_banana.add(banana)   <------The new logic works
banana.start()
launch_banana=False
new_banana=False**

#screen update

screen.blit(surf_ground, (0, 0))
all_sprites.draw(screen)
all_banana.draw(screen)
one_banana.draw(screen)
one_banana.update()
all_banana.update()
all_sprites.update()
monkey.launch()
pygame.display.flip()
pygame.time.Clock().tick(FPS)
#end principal cicle
pygame.quit()

有一种方法很简单吗？谢谢你在任何情况下