Python Pygame-永久调整主音量

我有一个在按键上播放正弦波音符的程序。这个想法是模拟一种仪器。我添加了一些调整音量的代码，但是每次播放新音符时，音量的这个值似乎都会刷新。如何调整此值，以便在按下键调整音量时，音量保持在此值，直到再次更改为止

import pygame
from pygame.locals import *

import math
import numpy

pygame.init()
bits = 16

pygame.mixer.pre_init(44100, -bits, 2)

def generate_sound(freq):
    volume = 0.5

    for i in range(pygame.mixer.get_num_channels()):
                c = pygame.mixer.Channel(i)
            c.set_volume(volume)

        for s in range(n_samples):
            t = float(s)/sample_rate    # time in seconds
            buf[s][0] = int(round(max_sample*math.sin(2*math.pi*freq*t)))    # left
            buf[s][1] = int(round(max_sample*math.sin(2*math.pi*freq*t)))    # right

        return pygame.sndarray.make_sound(buf)

size = (1200, 720)
screen = pygame.display.set_mode(size, pygame.HWSURFACE | pygame.DOUBLEBUF)


duration = 2.0          # in seconds

sample_rate = 44100

n_samples = int(round(duration*sample_rate))

#lower
sound_130_81 = generate_sound(130.81)   #C

_running = True
while _running:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            _running = False


        if event.type == KEYDOWN:
            #Volume control
            if event.key == K_1:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.1)

            elif event.key == K_2:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.2)

            elif event.key == K_3:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.3)

            elif event.key == K_4:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.4)

            elif event.key == K_5:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.5)

            elif event.key == K_6:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.6)

            elif event.key == K_7:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.7)

            elif event.key == K_8:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.8)

            elif event.key == K_9:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.9)

            elif event.key == K_0:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(1.0)

            elif event.key == K_BACKSPACE:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.0)

                volume = c.get_volume()

            if event.key == K_ESCAPE:
                _running = False

            #lower notes DOWN

            elif event.key == K_z:
                sound_130_81.play(-1)


        if event.type == KEYUP:

            #lower notes UP

            if event.key == K_z:
                sound_130_81.fadeout(350) #fade sound by .35 seconds

pygame.quit()

---

您正在“生成声音”方法开始时设置音量。您需要为其使用现有值，而不是每次都将其设置为固定值。可以将其作为可在调用者中调整的参数传入（最好是这样），也可以将其设置为全局值（如果您的语言支持）

我不太了解python，但它可能会像下面这样工作：

import pygame
from pygame.locals import *

import math
import numpy

pygame.init()
bits = 16
volume = 0.5

pygame.mixer.pre_init(44100, -bits, 2)

def generate_sound(freq, volume):

    for i in range(pygame.mixer.get_num_channels()):
                c = pygame.mixer.Channel(i)
            c.set_volume(volume)

        #setup our numpy array to handle 16 bit ints, which is what we set our mixer to expect with "bits" up above
        buf = numpy.zeros((n_samples, 2), dtype = numpy.int16)
        max_sample = 2**(bits - 1) - 1

        for s in range(n_samples):
            t = float(s)/sample_rate    # time in seconds
            buf[s][0] = int(round(max_sample*math.sin(2*math.pi*freq*t)))    # left
            buf[s][1] = int(round(max_sample*math.sin(2*math.pi*freq*t)))    # right

        return pygame.sndarray.make_sound(buf)

size = (1200, 720)
screen = pygame.display.set_mode(size, pygame.HWSURFACE | pygame.DOUBLEBUF)


duration = 2.0          # in seconds

sample_rate = 44100

n_samples = int(round(duration*sample_rate))


#lower
sound_130_81 = generate_sound(130.81, volume)   #C
sound_146_83 = generate_sound(146.83, volume)   #D
sound_164_81 = generate_sound(164.81, volume)   #E
sound_174_61 = generate_sound(174.61, volume)   #F
sound_196_00 = generate_sound(196.00, volume)   #G
sound_220_00 = generate_sound(220.00, volume)   #A
sound_246_94 = generate_sound(246.94, volume)   #B
#middle
sound_261_63 = generate_sound(261.63, volume)   #C
sound_293_66 = generate_sound(293.66, volume)   #D
sound_329_63 = generate_sound(329.63, volume)   #E
sound_349_23 = generate_sound(349.23, volume)   #F
sound_392_00 = generate_sound(392.00, volume)   #G
sound_440_00 = generate_sound(440.00, volume)   #A
sound_493_88 = generate_sound(493.88, volume)   #B
#higher
sound_523_25 = generate_sound(523.25, volume)   #C
sound_587_33 = generate_sound(587.33, volume)   #D
sound_659_25 = generate_sound(659.25, volume)   #E
sound_698_46 = generate_sound(698.46, volume)   #F
sound_783_99 = generate_sound(783.99, volume)   #G
sound_880_00 = generate_sound(880.00, volume)   #A
sound_987_77 = generate_sound(987.77, volume)   #B
sound_1046_50 = generate_sound(1046.50, volume) #C

#This will keep the sound playing forever, the quit event handling allows the pygame window to close without crashing
_running = True
while _running:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            _running = False


        if event.type == KEYDOWN:
            #Volume control
            if event.key == K_1:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.1)

            elif event.key == K_2:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.2)

            elif event.key == K_3:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.3)

            elif event.key == K_4:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.4)

            elif event.key == K_5:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.5)

            elif event.key == K_6:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.6)

            elif event.key == K_7:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.7)

            elif event.key == K_8:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.8)

            elif event.key == K_9:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.9)

            elif event.key == K_0:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(1.0)

            elif event.key == K_BACKSPACE:
                for i in range(pygame.mixer.get_num_channels()):
                    c = pygame.mixer.Channel(i)
                c.set_volume(0.0)

                volume = c.get_volume()

            if event.key == K_ESCAPE:
                _running = False

            #lower notes DOWN

            elif event.key == K_z:
                sound_130_81.play(-1)

            elif event.key == K_x:
                sound_146_83.play(-1)

            elif event.key == K_c:
                sound_164_81.play(-1)

            elif event.key == K_v:
                sound_174_61.play(-1)

            elif event.key == K_b:
                sound_196_00.play(-1)

            elif event.key == K_n:
                sound_220_00.play(-1)

            elif event.key == K_m:
                sound_246_94.play(-1)

            elif event.key == K_COMMA:
                sound_261_63.play(-1) 


            #middle notes DOWN

            elif event.key == K_a:
                sound_261_63.play(-1)

            elif event.key == K_s:
                sound_293_66.play(-1)

            elif event.key == K_d:
                sound_329_63.play(-1)

            elif event.key == K_f:
                sound_349_23.play(-1)

            elif event.key == K_g:
                sound_392_00.play(-1)

            elif event.key == K_h:
                sound_440_00.play(-1)

            elif event.key == K_j:
                sound_493_88.play(-1)

            elif event.key == K_k:
                sound_523_25.play(-1)


            #higher notes DOWN

            elif event.key == K_q:
                sound_523_25.play(-1)

            elif event.key == K_w:
                sound_587_33.play(-1)

            elif event.key == K_e:
                sound_659_25.play(-1)

            elif event.key == K_r:
                sound_698_46.play(-1)

            elif event.key == K_t:
                sound_783_99.play(-1)

            elif event.key == K_y:
                sound_880_00.play(-1)

            elif event.key == K_u:
                sound_987_77.play(-1)

            elif event.key == K_i:
                sound_1046_50.play(-1)

        if event.type == KEYUP:

            #lower notes UP

            if event.key == K_z:
                sound_130_81.fadeout(350) #fade sound by .35 seconds

            elif event.key == K_x:
                sound_146_83.fadeout(1000)

            elif event.key == K_c:
                sound_164_81.fadeout(350)

            elif event.key == K_v:
                sound_174_61.fadeout(350)

            elif event.key == K_b:
                sound_196_00.fadeout(350)

            elif event.key == K_n:
                sound_220_00.fadeout(350)

            elif event.key == K_m:
                sound_246_94.fadeout(350)

            elif event.key == K_COMMA:
                sound_261_63.fadeout(350)

            #middle notes UP

            elif event.key == K_a:
                sound_261_63.fadeout(350)

            elif event.key == K_s:
                sound_293_66.fadeout(350)

            elif event.key == K_d:
                sound_329_63.fadeout(350)

            elif event.key == K_f:
                sound_349_23.fadeout(350)

            elif event.key == K_g:
                sound_392_00.fadeout(350)

            elif event.key == K_h:
                sound_440_00.fadeout(350)

            elif event.key == K_j:
                sound_493_88.fadeout(350)

            elif event.key == K_k:
                sound_523_25.fadeout(350)

            #higher notes UP

            elif event.key == K_q:
                sound_523_25.fadeout(350)

            elif event.key == K_w:
                sound_587_33.fadeout(350)

            elif event.key == K_e:
                sound_659_25.fadeout(350)

            elif event.key == K_r:
                sound_698_46.fadeout(350)

            elif event.key == K_t:
                sound_783_99.fadeout(350)

            elif event.key == K_y:
                sound_880_00.fadeout(350)

            elif event.key == K_u:
                sound_987_77.fadeout(350)

            elif event.key == K_i:
                sound_1046_50.fadeout(350)

pygame.quit()

---

我已经试过了，但我看不到一种方法可以让它工作，我尝试的任何方法都会导致卷未定义。你能从我的代码中提供一个例子吗？我可以猜一猜，但我不懂python，也没有python开发环境。@user3856722:不要说“我尝试的任何东西最终都会导致卷未定义”，而是告诉我们你尝试了什么，以及发生了什么以及发生了什么（如果发生了异常，则进行完整的回溯）.我无法回顾我尝试过的所有内容，因为我做了很多变体，我基本上使用了上面的代码，在不同的地方定义了音量变量，但尝试过，例如，将音量设置为按键创建的当前音量的值，不管怎么说，不这样做没有什么不同的结果…@user3856722:这个答案中显示的代码不会“最终导致卷未定义”（我假设你的意思是

namererror

？），因此如果你看到的是这样的话，显然你没有实际运行这个代码。我们无法帮助您调试我们看不到的代码。删除所有无关的代码并放弃一个精简的示例将非常有帮助，只需演示问题即可。请参阅了解更多详细信息。我不确定有多少相关，因为相关部分都贯穿于整个代码中，而不仅仅是一个部分。请遵循MCVE的链接，它比我在简短的评论中解释得更好。但是您可以将其拆分为相关部分，即使它们都贯穿于整个代码中，并且只需要搭建足够的脚手架就可以将它们连接起来。例如，很明显，您不需要几十个调用来生成声音，几十个键处理程序等等来演示问题。