# 昨日知识点回顾

方法重构、驾驶飞船左右移动、全屏显示

飞船不移动解决，问题出在移动变量x更新

# Ship.py
 snip
    def update(self):
        """根据移动标志调整飞船的位置"""
        # 更新飞船而不是rect对象的x值
        # 如果飞船右移的标志和飞船外接矩形右边缘的x坐标 小于 屏幕右边缘x坐标，开始右移
        if self.moving_right and self.rect.right < self.screen_rect.right:
            self.x += self.settings.ship_speed
            # self.rect.x += self.settings.ship_speed
        # 如果飞船左移的标志和飞船外接矩形左边缘的x坐标 大于于 0，开始左移
        if self.moving_left and self.rect.left > 0:
            self.x -= self.settings.ship_speed
            # self.rect.x -= self.settings.ship_speed

        # 根据self.x 更新rect对象
        self.rect.x = self.x

# 今日知识点学习

12.8 射击

        12.8.1 添加子弹设置

# Settings.py
class Settings():
    """存储《外星人入侵》的所有设置的类"""

    def __init__(self):
        """初始化游戏的设置"""
        # 屏幕设置
        self.screen_width = int(1200)
        self.screen_height = int(800)
        self.bg_color = (230, 230, 230)

        # 飞船设置
        self.ship_speed = 1.5

        # 子弹设置
        self.bullet_speed = 1.0
        self.bullet_width = 3
        self.bullet_height = 15
        self.bullet_color = (60, 60, 60)

        12.8.2 创建Bullet类

#bullet.py
import pygame
from pygame.sprite import Sprite


class Bullet(Sprite):
    """管理飞船所发射的子弹"""

    def __init__(self, ai_game):
        """在飞船当前位置创建一个子弹对象"""
        super().__init__()
        self.screen = ai_game.screen
        self.settings = ai_game.settings
        self.color = self.settings.bullet_color

        # 在（0,0）处创建一个表示子弹的矩形，再设置正确的位置
        self.rect = pygame.Rect(0, 0, self.settings.bullet_width, self.settings.bullet_height)
        self.rect.midtop = ai_game.ship.rect.midtop

        # 存储用小数表示的子单位置
        self.y = float(self.rect.y)

    def update(self):
        """向上移动子弹"""
        # 更新表示子弹位置的小数值
        self.y -= self.settings.bullet_speed
        # 更新表示子弹的rect位置
        self.rect.y = self.y

    def draw_bullet(self):
        """在屏幕上绘制子弹"""
        pygame.draw.rect(self.screen, self.color, self.rect)

        12.8.3 将子弹存储在编组中

#主程序
import sys
import pygame
from Settings import Settings
from Ship import Ship


class AlienInvasion:
    """管理游戏资源和行为的类"""
    def __init__(self):
        """初始化游戏并创建游戏资源"""
        pygame.init()

        self.settings = Settings()
        # 非全屏运行
        self.screen = pygame.display.set_mode((self.settings.screen_width, self.settings.screen_height))

        # 全屏运行
        # self.screen = pygame.display.set_mode((0, 0), pygame.FULLSCREEN)
        # self.settings.screen_width = self.screen.get_rect().width
        # self.settings.screen_height = self.screen.get_rect().height
        pygame.display.set_caption("Alien Invasion")
        self.ship = Ship(self)
        # 创建用于存储子弹的编组
        self.bullets = pygame.sprite.Group()

    def run_game(self):
        """开始游戏的主循环"""
        while True:
            self._check_events()
            self.ship.update()
            # 更新子弹的位置
            self.bullets.update()
            self._update_screen()

        12.8.4 开火

import sys
import pygame
from Settings import Settings
from Ship import Ship
from bullet import Bullet


class AlienInvasion:
    """管理游戏资源和行为的类"""
    def __init__(self):
        """初始化游戏并创建游戏资源"""
        pygame.init()

        self.settings = Settings()
        # 非全屏运行
        self.screen = pygame.display.set_mode((self.settings.screen_width, self.settings.screen_height))

        # 全屏运行
        # self.screen = pygame.display.set_mode((0, 0), pygame.FULLSCREEN)
        # self.settings.screen_width = self.screen.get_rect().width
        # self.settings.screen_height = self.screen.get_rect().height
        pygame.display.set_caption("Alien Invasion")
        self.ship = Ship(self)
        self.bullets = pygame.sprite.Group()

    def run_game(self):
        """开始游戏的主循环"""
        while True:
            self._check_events()
            self.ship.update()
            self.bullets.update()
            self._update_screen()

    def _check_events(self):
        """响应按键和鼠标事件"""
        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):
        """响应按键"""
        if event.key == pygame.K_RIGHT:
            self.ship.moving_right = True
        elif event.key == pygame.K_LEFT:
            self.ship.moving_left = True
        elif event.key == pygame.K_q:
            sys.exit()
        elif event.key == pygame.K_SPACE:
            self._fire_bullet()

    def _check_keyup_events(self, event):
        """响应松开"""
        if event.key == pygame.K_RIGHT:
            self.ship.moving_right = False
        elif event.key == pygame.K_LEFT:
            self.ship.moving_left = False

    def _fire_bullet(self):
        """创建一颗子弹，并将其加入编组bullets中"""
        new_bullet = Bullet(self)
        self.bullets.add(new_bullet)

    def _update_screen(self):
        """更新屏幕上的图像，并切换到新屏幕。"""
        self.screen.fill(self.settings.bg_color)
        self.ship.blitme()
        for bullet in self.bullets.sprites():
            bullet.draw_bullet()

        # 让最近绘制的屏幕可见
        pygame.display.flip()


if __name__ == '__main__':
    # 创建游戏实例并运行游戏
    ai = AlienInvasion()
    ai.run_game()

        12.8.5 删除消失的子弹

    def run_game(self):
        """开始游戏的主循环"""
        while True:
            self._check_events()
            self.ship.update()
            self.bullets.update()
            # 删除消失的子弹
            for bullet in self.bullets.copy():
                if bullet.rect.bottom <= 0:
                    self.bullets.remove(bullet)
            print(len(self.bullets))
            self._update_screen() 

        12.8.6 限制子弹的数量

#Settings.py
# snip
# 子弹设置
        self.bullet_speed = 1.0
        self.bullet_width = 3
        self.bullet_height = 15
        self.bullet_color = (60, 60, 60)
        self.bullets_allowed = 3

#主程序
# snip
    def _fire_bullet(self):
        """创建一颗子弹，并将其加入编组bullets中"""
        if len(self.bullets) < self.settings.bullets_allowed:
            new_bullet = Bullet(self)
            self.bullets.add(new_bullet)

        12.8.7 创建方法_update_bullets()

    def run_game(self):
        """开始游戏的主循环"""
        while True:
            self._check_events()
            self.ship.update()
            self.bullets.update()
            self._update_bullets()
            # # 删除消失的子弹
            # for bullet in self.bullets.copy():
            #     if bullet.rect.bottom <= 0:
            #         self.bullets.remove(bullet)
            # print(len(self.bullets))
            self._update_screen()


    def _update_bullets(self):
        """更新子弹的位置并消除消失的子弹"""
        # 更新子弹的位置
        self.bullets.update()

        # 删除消失的子弹
        for bullet in self.bullets.copy():
            if bullet.rect.bottom <= 0:
                self.bullets.remove(bullet)

运行结果：