Python Can'；t正确移动pygame空间入侵者类

我正在尝试为大学制作一个太空入侵者游戏，我有大部分代码来获得通行证，我让外星人/入侵者向左、向下、向右移动，等等，但是我制作了一个类并导入了它，现在当我尝试使它工作时，它比应该向下移动的更右。我原以为我正确地看完了大学的幻灯片，但我想不出问题所在。我认为这可能与

xpo

数字有关

这是我的密码：

import sys, pygame, os, Invader
from pygame.locals import *

class SpaceInvaders:

    # Constructor of the basic game class.
    # This constructor calls initialize and main_loop method.
    def __init__(self):
        self.initialize()
        self.main_loop()

    # Initialization method. Allows the game to initialize different
    # parameters and load assets before the game runs
    def initialize(self):
        pygame.init()
        pygame.key.set_repeat(1, 1) # This means when I hold A or D it repeats it for you so it doesn't move only a little
        os.environ['SDL_VIDEO_CENTERED'] = '1' # centres the game in the window on launch
        self.width = 1260
        self.height = 700
        self.screen = pygame.display.set_mode((self.width, self.height))

        self.caption = "Space Invaders!"    # This makes the top window say "Brick Breaker"
        pygame.display.set_caption(self.caption)

        self.framerate = 60

        self.clock = pygame.time.Clock()

        # Sprites
        self.background = pygame.image.load("background.jpg")
        self.defender = pygame.image.load("defender.png")
        self.alien = pygame.image.load("alien1.png")
        self.rocket = pygame.image.load("rocket.png")

        # Locations
        self.defenderPosX = 570
        self.defenderPosY = 610

        self.rocketPosX = -1
        self.rocketPosY = -1

        self.rocketFired = False

        self.alienDirection = -1
        self.alienSpeed = -1

        self.ticks = 0

        self.invaders = []
        xPos = 300
        for i in range(11):
            invader = Invader.Invader()
            invader.setPosX(xPos)
            invader.setPosY(100)
            self.invaders.append(invader)
            xPos += 65


    # main loop method keeps the game running. This method continuously
    # calls the update and draw methods to keep the game alive.
    def main_loop(self):        
        while True:
            gametime = self.clock.get_time()
            self.update(gametime)
            self.draw(gametime)
            self.clock.tick(self.framerate)

    # Update method contains game update logic, such as updating the game
    # variables, checking for collisions, gathering input, and
    # playing audio.
    def update(self, gametime):
        events = pygame.event.get()

        for event in events:
            if event.type == pygame.QUIT:
                pygame.quit()
                sys.exit()

            if event.type ==pygame.KEYDOWN:
                if event.key == pygame.K_ESCAPE:    # Makes the game exit when you press escape
                    pygame.quit()
                    sys.exit()

            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_a or event.key == pygame.K_LEFT:       # Makes the Defender move left
                    self.defenderPosX = self.defenderPosX - 15
                elif event.key == pygame.K_d or event.key == pygame.K_RIGHT:    # Makes the Defender move right
                    self.defenderPosX = self.defenderPosX + 15
                elif event.key == pygame.K_SPACE and self.rocketFired == False: # Makes the defender shoot a rocket
                    self.rocketPosX = self.defenderPosX + 47                    # Position of the rocekt on launch
                    self.rocketPosY = 620 - self.rocket.get_height()            # Position of the rocket on launch
                    self.rocketFired = True

        if self.rocketFired == True:
                self.rocketPosY = self.rocketPosY - 10  # If True, the rocket will move up 10px

        if self.rocketPosY < 10:
                self.rocketFired = False                # When it reaches 10px it'll reset the variable to False to start again

        # Stopping the aliens and rocket from going off screen

        if self.defenderPosX < 0:
            self.defenderPosX = 0

        if self.defenderPosX > 1156:
            self.defenderPosX = 1156

        if self.rocketPosX < 48:
            self.rocketPosX = 48

        if self.rocketPosX > 1204:
            self.rocketPosX = 1204

        self.ticks = self.ticks + gametime
        if self.ticks > 500:
            for i in range(11):
                self.invaders[i].moveHorizontal(self.alienSpeed * self.alienDirection)

            if self.invaders[0].getPosX() < 100:
                self.alienDirection = +1

                xPos = 96
                for i in range(11):
                    self.invaders[i].moveVertical(8)
                    self.invaders[i].setPosX(xPos)
                    #xPos = xPos + self.alien.get_width()

            if self.invaders[10].getPosX() > 1160:
                self.invaderDirection = -1

                xPos = 1260 - self.alien.get_width() * 11
                for i in range(11):
                    self.invaders[i].moveVertical(8)
                    self.invaders[i].setPosX(xPos)
                    #xPos = xPos + self.alien.get_width()

            self.ticks = 0          
    # Draw method, draws the current state of the game on the screen
    def draw(self, gametime):
        self.screen.blit(self.background, (0, 0))
        self.screen.blit(self.defender, (self.defenderPosX, self.defenderPosY))
        for i in range(11):
            self.screen.blit(self.alien, self.invaders[i].getPosition())
        if self.rocketFired == True:
            self.screen.blit(self.rocket, (self.rocketPosX, self.rocketPosY))



        #self.sprites.update()
        pygame.display.flip()


if __name__ == "__main__":
    game = SpaceInvaders()

---

不应该有一个基于i的偏移量吗？为什么最后一行被注释掉了？

我不知道您在这个项目中是否有一些限制，比如您可以使用或不使用哪些函数和类，但是如果您只使用自定义事件检查，它会简单得多

你能把你的精灵上传到公众可以下载的地方吗？在调试代码时使用相同的图像会很有帮助。

class Invader:
    def __init__(self):
        self.__alienPosX = 0
        self.__alienPosY = 50

    def setPosX(self, x):
        self.__alienPosX = x

    def setPosY(self, y):
        self._alienPosY = y

    def getPosX(self):
        return self.__alienPosX

    def getPosY(self):
        return self.__alienPosY

    def getPosition(self):
        return (self.__alienPosX, self.__alienPosY)

    def moveHorizontal(self, amount):
        self.__alienPosX = self.__alienPosX + amount

    def moveVertical(self, amount):
        self.__alienPosY = self.__alienPosY + amount

if self.invaders[0].getPosX() < 100:
                self.alienDirection = +1

if self.invaders[10].getPosX() > 1160:
                self.invaderDirection = -1

for i in range(11):
                    self.invaders[i].moveVertical(8)
                    self.invaders[i].setPosX(xPos)
                    #xPos = xPos + self.alien.get_width()