無法在pygame中移動捕手角色

Question

嘗試制作一款讓我的接球手接住棒球的游戲。 如果棒球被接住，屏幕頂部會隨機出現一個新棒球。 做出更改后，我似乎無法移動捕手。 游戲是通過python和pygame制作的。

捕捉.py

import sys
import pygame
from pygame.sprite import Group
from settings import Settings
from catcher import Catcher
from baseball import Baseball
import game_functions as gf

def run_game():
    """Initializes the game, screen, and settings."""
    pygame.init()
    ai_settings = Settings()
    screen = pygame.display.set_mode((ai_settings.screen_width, ai_settings.screen_height))
    pygame.display.set_caption("Catch")

    catcher = Group()
    baseball = Group()

    while True:
        gf.check_events(catcher)
        gf.update_catcher(ai_settings, screen, catcher)
        gf.update_baseball(ai_settings, screen, catcher, baseball)
        gf.update_screen(ai_settings, screen, catcher, baseball)

run_game()

棒球.py

import pygame
from pygame.sprite import Sprite

class Baseball(Sprite):
    """A class to represent a baseball."""

    def __init__(self, ai_settings, screen):
        super().__init__()
        self.screen = screen
        self.ai_settings = ai_settings

        # Load the baseball image and set its rect attribute.
        self.image = pygame.image.load('images/baseball.bmp')
        self.rect = self.image.get_rect()

        # Start each new baseball at a random position at the top of the screen.
        self.rect.x = self.rect.width
        self.rect.y = self.rect.height 

        # Store the alien's exact position.
        self.x = float(self.rect.x)
        self.y = float(self.rect.y)

    def blitme(self):
        """Draw the baseball at tis current location."""
        self.screen.blit(self.image, self.rect)

    def update(self):
        """Dropping the baseball."""
        self.y += self.ai_settings.baseball_drop_speed
        self.rect.y = self.y

捕手.py

import pygame
from pygame.sprite import Sprite

class Catcher(Sprite):

    def __init__(self, ai_settings, screen):
        """Initialize the catcher and set its starting position."""
        super().__init__()
        self.screen = screen
        self.ai_settings = ai_settings

        # Load the catcher image and get its rect.
        self.image = pygame.image.load('images/catcher.bmp')
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()

        # Start each new catcher at the bottom center of the screen.
        self.rect.centerx = self.screen_rect.centerx
        self.rect.bottom = self.screen_rect.bottom

        # Store a decimal value for the catcher's center.
        self.center = float(self.rect.centerx)

        # Movement flags
        self.moving_right = False
        self.moving_left = False

    def update(self, ai_settings, screen):
        """Update the catcher's position baed on the movement flag."""
        # Update the catcher's center value, not the rect.
        if self.moving_right and self.rect.right <= self.screen_rect.right:
            self.center += self.ai_settings.catcher_speed_factor
        if self.moving_left and self.rect.left >= 0:
            self.center -= self.ai_settings.catcher_speed_factor

        # Update rect object from self.center.
        self.rect.centerx = self.center

    def blitme(self):
        """Draw the catcher at its current location."""
        self.screen.blit(self.image, self.rect)

游戲函數.py

import sys
import pygame

from baseball import Baseball
from catcher import Catcher
from random import randint

def check_keydown_events(event, catcher):
    """Respond to keypresses."""
    if event.key == pygame.K_RIGHT:
        catcher.moving_right = True
    elif event.key == pygame.K_LEFT:
        catcher.moving_left = True
    elif event.key == pygame.K_q:
        sys.exit()

def check_keyup_events(event, catcher):
    """Respond to key releases."""
    if event.key == pygame.K_RIGHT:
        catcher.moving_right = False
    elif event.key == pygame.K_LEFT:
        catcher.moving_left = False

def check_events(catcher):
    """Respond to keypresses and mouse events."""
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event, catcher)
        elif event.type == pygame.KEYUP:
            check_keyup_events(event, catcher)

def update_screen(ai_settings, screen, catcher, baseball):
    """Update images on the screen and flip to the new screen."""
    # Redraw the screen during each pass through the loop.
    screen.fill(ai_settings.bg_color)
    catcher.draw(screen)
    baseball.draw(screen)
    # Make the most recently drawn screen visible.
    pygame.display.flip()

def update_baseball(ai_settings, screen, catcher, baseball):
    """Update the positions of the baseball and detect collisions."""
    screen_rect = screen.get_rect()
    baseball.update()
    if len(baseball) == 0:
        new_ball = Baseball(ai_settings, screen)
        new_ball.x = randint(new_ball.rect.width, screen_rect.right - new_ball.rect.width)
        new_ball.rect.x = new_ball.x
        new_ball.y = new_ball.rect.height
        new_ball.rect.y = new_ball.y
        baseball.add(new_ball)
    collisions = pygame.sprite.groupcollide(baseball, catcher, True, False)

def update_catcher(ai_settings, screen, catcher):
    screen_rect = screen.get_rect()
    catcher.update(ai_settings, screen)
    if len(catcher) == 0:
        new_catcher = Catcher(ai_settings, screen)
        new_catcher.center = screen_rect.centerx
        new_catcher.rect.centerx = new_catcher.center
        new_catcher.rect.bottom = screen_rect.bottom
        catcher.add(new_catcher)

設置.py

import pygame

class Settings():
    """Class to store settings."""

    def __init__(self):
        """Initializes the game's settings."""
        # Screen settings.
        self.screen_width = 800
        self.screen_height = 600
        self.bg_color = (255, 255, 255)

        # Ship settings.
        self.catcher_speed_factor = 1.5

        # Baseball settings.
        self.baseball_drop_speed = float(1 / 2)

Answer 1

問題是catcher是Group而不是Catcher(Sprite)的實例：

 catcher = Group() while True: check_events(catcher)

這導致屬性moving_right和moving_left分別設置為check_keyup_events中的Group對象check_keydown_events 。

您必須更改Group中對象的屬性：

def check_keydown_events(event, catcher):
    """Respond to keypresses."""
    if event.key == pygame.K_RIGHT:
        for c in catcher:
            c.moving_right = True
    elif event.key == pygame.K_LEFT:
        for c in catcher:
            c.moving_left = True
    elif event.key == pygame.K_q:
        sys.exit()

def check_keyup_events(event, catcher):
    """Respond to key releases."""
    if event.key == pygame.K_RIGHT:
        for c in catcher:
            c.moving_right = False
    elif event.key == pygame.K_LEFT:
        for c in catcher:
            c.moving_left = False