当玩家误击目标三次以上时结束游戏

Question

我试着做python速成课程练习14-2，这是在屏幕的右边缘创建一个矩形，它以稳定的速度上下移动。然后在屏幕的左边缘出现一条船，玩家可以在向移动的矩形目标发射子弹时上下移动。添加一个开始游戏的播放按钮，玩家三次错过目标，结束游戏并使播放按钮重新出现。让玩家用play按钮重新启动游戏

游戏正常运行，对象按程序移动，关键事件也被检测到并相应地上下移动，但它没有检测到将游戏状态设置为False的条件。因此，play_按钮永远不会出现，即使玩家三次以上未击中目标，游戏也会继续进行

我把子弹设定为一次发射一颗，这样更容易用眼睛看到，也更容易测试

我认为我的if len(self.bullets) >= self.settings.firing_limit and not pygame.sprite.spritecollideany(self.rectangle, self.bullets):语句是错误的，因为我只是自己想出来的，因为从我的编程水平来看，我不知道如何计算缺少目标的子弹数。如果我错了，请纠正我

下面是运行游戏的主文件

target_practice.py

---

import pygame
import sys
from time import sleep

from settings_target_practice import Settings 
from ship import Ship 
from bullet import Bullet 
from rectangle import Rectangle 
from game_stats import GameStats
from button import Button 

class TargetPractice:
    def __init__(self):
        pygame.init()
        self.settings = Settings()
        self.screen = pygame.display.set_mode((self.settings.screen_width, 
                        self.settings.screen_height))
        pygame.display.set_caption("Target Practice")
        self.stats = GameStats(self)
        self.ship = Ship(self)
        self.rectangle = Rectangle(self)
        self.bullets = pygame.sprite.Group()
        self.play_button = Button(self, "Play")

    def run_game(self):
        while True:
            self._check_events()
            if self.stats.game_active:
                self.ship.update()
                self._update_bullet()
                self._update_rectangle()
            self._update_screen()

    def _fire_bullet(self):
        new_bullet = Bullet(self)
        if len(self.bullets)  < self.settings.bullets_allowed:
            self.bullets.add(new_bullet)

    def _update_bullet(self):
        self.bullets.update()
        self.screen_rect = self.screen.get_rect()
        for bullet in self.bullets:
            self._check_bullet_rectangle_collision()
        for bullet in self.bullets.copy():
            if bullet.rect.left >= self.screen_rect.right:
                self.bullets.remove(bullet)

    def _update_rectangle(self):
        self.rectangle.update()
        self._rectangle_check_edges()

    def _rectangle_check_edges(self):
        if self.rectangle.check_edges():
            self._change_direction()

    def _change_direction(self):
        self.settings.rectangle_direction *= -1

    def _check_bullet_rectangle_collision(self):
        if pygame.sprite.spritecollideany(self.rectangle, self.bullets):
            self._start_game()
        if len(self.bullets) >= self.settings.firing_limit and not pygame.sprite.spritecollideany(self.rectangle, self.bullets):
            self.stats.game_active = False
            pygame.mouse.set_visible(True)

    def _check_events(self):
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                sys.exit()
            elif event.type == pygame.KEYDOWN:
                self._check_keydown_events(event)
            elif event.type == pygame.KEYUP:
                self._check_keyup_events(event)

    def _check_keydown_events(self, event):
        if event.key == pygame.K_q:
            sys.exit()
        elif event.key == pygame.K_UP:
            self.ship.moving_up = True
        elif event.key == pygame.K_DOWN:
            self.ship.moving_down = True
        elif event.key == pygame.K_SPACE:
            self._fire_bullet()
        elif event.key == pygame.K_p:
            self._check_play_button( )

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

    def _check_play_button(self):
        if not self.stats.game_active:
            self.stats.reset_stats()
            self.stats.game_active = True
            self._start_game()

    def _start_game(self):
        if self.stats.game_active:
            #Get rid of any bullets.
            self.bullets.empty()

            #Create a new fleet and center the ship.
            self.rectangle.draw()
            self.ship.center_ship()

            #Hide the mouse curser
            pygame.mouse.set_visible(True)

            sleep(0.5)


    def _update_screen(self):
        self.screen.fill(self.settings.bg_color)
        self.ship.blitme()
        for bullet in self.bullets:
            bullet.draw_bullet()
        self.rectangle.draw()
        if self.stats.game_active:
            pygame.mouse.set_visible(False)
        if not self.stats.game_active:
            self.play_button.draw_button()

        pygame.display.flip()

    if __name__ == '__main__':
        tp_game = TargetPractice()
        tp_game.run_game()

---

以下是补充上述主文件的文件

ship.py

---

import pygame
class Ship:
    def __init__(self, tr_game):
        self.screen = tr_game.screen
        self.settings = tr_game.settings
        self.screen_rect = self.screen.get_rect()

        self.image = pygame.image.load('images/ship.bmp')
        self.rect = self.image.get_rect()


        self.rect.midleft = self.screen_rect.midleft

        self.y = self.rect.y
        self.moving_up = False
        self.moving_down = False

    def blitme(self):
        self.screen.blit(self.image, self.rect)

    def update(self):
        if self.moving_up and self.rect.top > self.screen_rect.top:
            self.y -= self.settings.ship_speed
        if self.moving_down and self.rect.bottom < self.screen_rect.bottom:
            self.y += self.settings.ship_speed

        self.rect.y = self.y

    def center_ship(self):
        self.rect.midleft = self.screen_rect.midleft
        self.y = float(self.rect.y)

---

复角

---

import pygame.font
class Rectangle:

    def __init__(self, tp_game):
        self.screen = tp_game.screen
        self.screen_rect = self.screen.get_rect()
        self.rectangle_width, self.rectangle_height = 200, 50
        self.rectangle_color = (0, 0, 255)
        self.rect = pygame.Rect(0, 0, self.rectangle_width, 
                    self.rectangle_height)
        self.rect.midright = self.screen_rect.midright
        self.settings = tp_game.settings

        self.y = float(self.rect.y)

    def update(self):
        self.y += self.settings.rectangle_speed * self.settings.rectangle_direction
        self.rect.y = self.y

    def check_edges(self):
        if self.rect.bottom >= self.screen_rect.bottom or self.rect.top <= 0:
            return True

    def draw(self):
         pygame.draw.rect(self.screen, self.rectangle_color, self.rect)

---

子弹头

---

from pygame.sprite import Sprite
import pygame

class Bullet(Sprite):
    def __init__(self, tr_game):
        super().__init__()
        self.screen = tr_game.screen
        self.settings = tr_game.settings
        self.color = self.settings.bullet_color
        self.rect = pygame.Rect(0, 0, self.settings.bullet_width, 
                    self.settings.bullet_height)
        self.rect.midright = tr_game.ship.rect.midright
        self.x = float(self.rect.x)

    def update(self):
        self.x += self.settings.bullet_speed
        self.rect.x = self.x

    def draw_bullet(self):
        pygame.draw.rect(self.screen, self.color, self.rect) 

---

设置.py

---

class Settings:
    def __init__(self):
        self.screen_width = 1400
        self.screen_height = 700
        self.bg_color = (255, 255, 255)

        self.ship_speed = 1.5
        self.firing_limit = 3

        self.bullet_speed = 2
        self.bullet_width = 15
        self.bullet_height = 5
        self.bullet_color = (60, 60, 60)
        self.bullets_allowed = 1

        self.rectangle_speed = 1.0
        self.rectangle_direction = 1

---

game_stats.py

---

class GameStats:
    def __init__(self, rp_game):
        self.settings = rp_game.settings
        self.reset_stats()
        self.game_active = True

    def reset_stats(self):
        self.player_chance = self.settings.firing_limit

---

button.py

---

import pygame.font
class Button:

    def __init__(self, tp_game, msg):
        """Initialize button attributes."""
        self.screen = tp_game.screen
        self.screen_rect = self.screen.get_rect()

        #Set the dimensions and properties of the button.
        self.width, self.height = 200, 50
        self.button_color = (0, 255, 0)
        self.text_color = (255, 255, 255)
        self.font = pygame.font.SysFont(None, 48)

        #Build the button's rect object and center it.
        self.rect = pygame.Rect(0, 0, self.width, self.height)
        self.rect.center = self.screen_rect.center

        #The button message needs to be prepped only once.
        self._prep_msg(msg)

    def _prep_msg(self, msg):
        """Turn message into a rendered image and center text on the screen."""
        self.msg_image = self.font.render(msg, True, self.text_color, 
                        self.button_color)
        self.msg_image_rect = self.msg_image.get_rect()
        self.msg_image_rect.center = self.rect.center

    def draw_button(self):
        #Draw blank button and then draw message.
        self.screen.fill(self.button_color, self.rect)
        self.screen.blit(self.msg_image, self.msg_image_rect)

---

Answer 1

项目符号是包含在^{}{}中的^{}。
如果要从所有Group中删除Sprite，则只需在Sprite实例上调用方法^{}。e、 g:

bullet.kill()

要计算未命中数，请向类添加属性（self.missed）。如果子弹离开屏幕，则增量self.missed，如果超过限制，则结束游戏：

class TargetPractice:
    def __init__(self):
        pygame.init()
        self.settings = Settings()
        self.screen = pygame.display.set_mode((self.settings.screen_width, 
                        self.settings.screen_height))
        pygame.display.set_caption("Target Practice")
        self.stats = GameStats(self)
        self.ship = Ship(self)
        self.rectangle = Rectangle(self)
        self.bullets = pygame.sprite.Group()
        self.play_button = Button(self, "Play")

        self.missed = 0 # <  

    # [...]

    def _update_bullet(self):
        self.bullets.update()
        self.screen_rect = self.screen.get_rect()
        for bullet in self.bullets:
            self._check_bullet_rectangle_collision()

        # find missing bullets and increment the counter for each      
        for bullet in self.bullets:

            if bullet.rect.left >= self.screen_rect.width: 
                bullet.kill()
                self.missed += 1
                if self.missed >= 3:
                    self.stats.game_active = False
                    pygame.mouse.set_visible(True)