Pygame飞船仅上下移动(左右正在工作)

Question

此部分是gamefunction.py file

import sys
import pygame
def check_keydown_events(event,ship):
    """Respond to the keypressess."""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = True
    elif event.key == pygame.K_LEFT:
        ship.moving_left = True
    elif event.key == pygame.K_UP:
        ship.moving_up = True
    elif event.key == pygame.K_DOWN:
        ship.moving_down = True 

def check_keyup_events(event, ship):
    """Respond to the keyreleases."""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False
    elif event.key == pygame.K_LEFT:
        ship.moving_left = False
    elif event.key == pygame.K_UP:
        ship.moving_up = False
    elif event.key == pygame.K_DOWN:
        ship.moving_down = False
def check_events(ship):
    """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,ship)
        elif event.type == pygame.KEYUP:
            check_keyup_events(event, ship)

这是命名为ship.py

import pygame
class Ship():
    def __init__(self,ai_settings,screen):
        """Initialize the ship and set its starting position."""
        self.screen = screen
        self.ai_settings = ai_settings
        #Load the ship image and get its rect.
        self.image = pygame.image.load('images/ship.png')
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()
        #Start each new ship 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 ship's center.
        self.center = float(self.rect.centerx) 
        #Movement Flags
        self.moving_right = False
        self.moving_left = False
        self.moving_up = False
        self.moving_down = False

    def update(self):
        """Update the ship's position based on the movement flag."""
        #Update the ship's center value, not the rect
        if self.moving_right and self.rect.right<self.screen_rect.right:
            self.center += self.ai_settings.ship_speed_factor
        if self.moving_left and self.rect.left>0:
            self.center -= self.ai_settings.ship_speed_factor 
        #Up-dwon motion added ***Please check the logic for 1200x800 screen*** 
        if self.moving_up and self.rect.top<self.screen_rect.top:
            self.center += self.ai_settings.ship_speed_factor
        if self.moving_down and self.rect.bottom>800:
            self.center -= self.ai_settings.ship_speed_factor
        #Update rect object from self.center.
        self.rect.centerx = self.center

Answer 1

来源：Python速效课程

ship.py中只有几个镊子：

在self.center = float(self.rect.centerx)下，添加self.bottom = float(self.rect.bottom)并更改：

if self.moving_up and self.rect.top<self.screen_rect.top:
    self.center += self.ai_settings.ship_speed_factor
if self.moving_down and self.rect.bottom>800:
    self.center -= self.ai_settings.ship_speed_factor

to：

if self.moving_up and self.rect.top<self.screen_rect.top:
    self.bottom -= self.ai_settings.ship_speed_factor
if self.moving_down and self.rect.bottom<800:
    self.bottom += self.ai_settings.ship_speed_factor

最后，在self.rect.centerx = self.center下，添加self.rect.bottom = self.bottom。

这应该使您能够在游戏中上下上下！

Answer 2

这是我在这些功能中发现的问题：

check_keydown_events
check_keyup_events
check_events

在每种情况下，您都在执行if-elif-elif-elif语句。这意味着，当if语句是True时，elif语句将无法运行。

在您的情况下，如果按下左键或右键，您将永远无法向上或向下移动。

您应该更改此代码，以便您仅将if-elif与向上/向下/向左/右移动一起使用。

这是一个(校正(示例：

if event.key == pygame.K_RIGHT:
    ship.moving_right = True
elif event.key == pygame.K_LEFT:
    ship.moving_left = True
if event.key == pygame.K_UP:
    ship.moving_up = True
elif event.key == pygame.K_DOWN:
    ship.moving_down = True

如果将每个if-elif-elif-elif语句更改为if-elif-if-elif。

Answer 3

ship.py

.....
self.bottom = float(self.rect.bottom)
self.moving_up = False
self.moving_down = False
def update(self):
    .....
    # check if the ship is moving up and stop the ship to move up if 
    # it's top edge position is less than 
    # screen's top (top right corner is 0,0) position
    if self.moving_up and self.rect.top > self.screen_rect.top:
        self.bottom -= self.ai_settings.ship_speed_factor
    # check if the ship is moving down and stop the ship when it's
    # bottom position is greater than the screen bottom edge position.
    if self.moving_down and self.rect.bottom < self.screen_rect.bottom:
        self.bottom += self.ai_settings.ship_speed_factor
    self.rect.bottom = self.bottom

game_function.py

def check_keydown_event(event, ship):
    """Respond to keypresses"""
    ....
    elif event.key == pygame.K_UP:
        ship.moving_up = True
    elif event.key == pygame.K_DOWN:
        ship.moving_down = True

def check_keyup_event(event, ship):
    ....
    elif event.key == pygame.K_UP:
        ship.moving_up = False
    elif event.key == pygame.K_DOWN:
        ship.moving_down = False