函数不会在命令上运行

Question

游戏在主菜单上开始，当鼠标悬停在开始上方按下回车键时，淡出功能运行，然后是黑屏功能，最后是游戏功能。但是，运行main_menu函数，并且在按下键事件时，只运行语句中的播放声音。

import os
import pygame 
import pygame_menu
from pygame import mixer
from pygame.locals import *
import sys 

# Initialization
pygame.mixer.init()
pygame.init() 


# Center the Game Application
os.environ['SDL_VIDEO_CENTERED'] = '1'

# Game Resolution
width=800
height=600
screen=pygame.display.set_mode((width, height))

# Text Renderer
def text_format(message, textFont, textSize, textColor):
newFont=pygame.font.Font(textFont, textSize)
newText = newFont.render(message, 0, textColor)

return newText


# Colors
white=(255, 255, 255)
black=(0, 0, 0)
gray=(50, 50, 50)
red=(255, 0, 0)
green=(0, 255, 0)
blue=(0, 0, 255)
yellow=(255, 255, 0)
AMP_PINK=(242, 145, 233)

# Game Fonts
hamberger = "./assets/fonts/hamberger.ttf"


# Sounds
menukeys = mixer.Sound("assetssoundskeypress.wav")

mixer.music.load("assetssoundsstrolling.wav")
mixer.music.play(-1)

# Game Framerate
clock = pygame.time.Clock()
FPS=60

def game():
main_menu()
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
exit()
screen.fill((0,255,0))
pygame.display.update()



def black_screen():
blacc = pygame.Surface((width,height))
blacc.fill((0,0,0))
pygame.display.update()
pygame.time.delay(2)
game()

def fade(): 
global width, height
fade = pygame.Surface((width,height))
fade.fill((0,0,0))
for alpha in range(0, 300):
fade.set_alpha(alpha)
screen.blit(fade, (0,0))
pygame.display.update()
pygame.time.delay(6)
black_screen()

# Main Menu
def main_menu():

menu=True
selected="start"

while menu:
for event in pygame.event.get():
if event.type==pygame.QUIT:
pygame.quit()
quit()
if event.type==pygame.KEYDOWN:
if event.key==pygame.K_UP:
mixer.Sound.play(menukeys)
selected="start"
elif event.key==pygame.K_DOWN:
mixer.Sound.play(menukeys)
selected="quit"
if event.key==pygame.K_RETURN:
#Starts the game
mixer.Sound.play(menukeys)
if selected=="start":
fade()
if selected=="quit":
mixer.Sound.play(menukeys)
pygame.quit()
quit()

# Main Menu UI
screen.fill(AMP_PINK)
title=text_format("SNATCHED", hamberger, 90, black)
if selected=="start":
text_start=text_format("START", hamberger, 75, white)
else:
text_start = text_format("START", hamberger, 75, black)
if selected=="quit":
text_quit=text_format("QUIT", hamberger, 75, white)
else:
text_quit = text_format("QUIT", hamberger, 75, black)

title_rect=title.get_rect()
start_rect=text_start.get_rect()
quit_rect=text_quit.get_rect()

# Main Menu Text
screen.blit(title, (width/2 - (title_rect[2]/2), 80))
screen.blit(text_start, (width/2 - (start_rect[2]/2), 300))
screen.blit(text_quit, (width/2 - (quit_rect[2]/2), 360))
pygame.display.update()
clock.tick(FPS)
pygame.display.set_caption("Snatched - Main Menu")

#Initialize the Game
main_menu()
pygame.quit()
quit()

Answer 1

名称fade使用了两次。函数和函数中的pygame.Surface对象都称为fade。