我正在为使用Pygame编写的菜单创建一些按钮，当我注意到一些似乎没有加起来的东西时。以下是代码目前的样子：
#Load up the modules
import pygame, time, random, linecache
pygame.init()
#Let's get some basic colours stored.
black = (0,0,0)
gray = (123,123,123)
white = (255,255,255)
red = (200,0,0)
bright_red = (255,0,0)
green = (0,200,0)
bright_green = (0,255,0)
blue = (0,0,200)
bright_blue = (0,0,255)
yellow = (225,225,0)
bright_yellow = (255,255,0)
#Loading up a time obect function for later.
clock = pygame.time.Clock()
#This function is necessary all round.
#n is the line to be read.
def readline(file, n):
current_line = linecache.getline(file , n)
current_line = current_line[:-1]
return current_line
#Let's set the screen dimensions based on the options file.
screen_width = int(readline('Options.txt', 2))
screen_height = int(readline('Options.txt', 3))
game_display = pygame.display.set_mode((screen_width,screen_height))
pygame.display.set_caption('Le jeux')
#Functions for displaying text.
def text_objects(text, font, colour):
textSurface = font.render(text, True, colour)
return textSurface, textSurface.get_rect()
def message_display(text, x_ordinate, y_ordinate, font_size, colour):
#Consider letting the font be a paramter.
largeText = pygame.font.Font("freesansbold.ttf",font_size)
TextSurf, TextRect = text_objects(text, largeText, colour)
TextRect.center = (x_ordinate,y_ordinate)
game_display.blit(TextSurf, TextRect)
def button(x, y, width, height, active_colour, inactive_colour, message, font_size, function):
if(x <= mouse[0]/screen_width <= x + width and y <= mouse[1]/screen_height <= y + height):
pygame.draw.rect(game_display, active_colour, (x * screen_width, y * screen_height, width * screen_width, height * screen_height))
message_display(message, round(screen_width * (x + width/2)), round(screen_height * (y + height/2)), round(font_size * screen_height), black)
function
else:
pygame.draw.rect(game_display, inactive_colour, (x * screen_width, y * screen_height, width * screen_width, height * screen_height))
message_display(message, round(screen_width * (x + width/2)), round(screen_height * (y + height/2)), round(font_size * screen_height), black)
def my_test(x, y, width, height):
if(x <= mouse[0]/screen_width <= x + width and y <= mouse[1]/screen_height <= y + height):
#The line above seems completely redundant yet for some reason is essential
print("hi")
#Creating a few variables for the loops to come.
viewing_menu = True
playing_game = False
#Showing a very basic menu.
while viewing_menu == True:
for event in pygame.event.get():
if(event.type == pygame.QUIT) :
viewing_menu = False
#Determining the mouse's current position
mouse = pygame.mouse.get_pos()
game_display.fill(white)
button(0.25, 0.1, 0.5, 0.2, bright_green, green, 'Play', 0.15, my_test(0.25, 0.1, 0.5, 0.2))
#button(0.25, 0.4, 0.5, 0.2, bright_yellow, yellow, 'Options', 0.15, my_test())
#button(0.25, 0.7, 0.5, 0.2, bright_red, red, 'Quit', 0.15, my_test())
pygame.display.update()
clock.tick(60)
pygame.quit()
quit()
像这样，当我的鼠标盘旋在播放按钮上时，python会不断打印“hi”，这正是我此时想要的。问题是，第65行if(x <= mouse[0]/screen_width <= x + width and y <= mouse[1]/screen_height <= y + height):似乎浪费了空间和时间，因为函数my_test只应该被调用，而第58行（完全相同）才是真的。也就是说我两次评估相同的情况。
出于某种原因，如果我对该行进行评论，则无论鼠标的位置如何，都会连续打印出“hi”。目前这不是一个大问题（考虑到它的早期），但我认为必须多次评估相同条件可能会在开始变得重要时降低性能。
我需要知道的是为什么似乎无条件地调用my_test函数。
提前感谢您的帮助。
答案 0 :(得分：0)
当您调用my_test(0.25, 0.1, 0.5, 0.2)函数时，您可以调用button()作为参数之一，因此每次迭代都会调用mytest()和button()。
button(0.25, 0.1, 0.5, 0.2, bright_green, green, 'Play', 0.15, my_test(0.25, 0.1, 0.5, 0.2))
^^ right there
你应该传递函数本身：
button(0.25, 0.1, 0.5, 0.2, bright_green, green, 'Play', 0.15, my_test)
在内部按钮（）中，您可以调用它：
def button(x, y, width, height, active_colour, inactive_colour, message, font_size, function):
if(x <= mouse[0]/screen_width <= x + width and y <= mouse[1]/screen_height <= y + height):
#...
function(x,y,width,height)
这可以让你改变button（）调用的功能。如果它始终是mytest() you could call mytest（）directly from button() and omit the last argument to按钮（）`。