<Python編程>

外星人入侵游戲編程練習(xí)

1.鍵盤(pán)不動(dòng)事件

找了半天,找不到鍵盤(pán)按下,飛船不動(dòng)是什么原因,然后仔細(xì)對(duì)照自己的代碼和書(shū)上的代碼,發(fā)現(xiàn)事件監(jiān)聽(tīng)錯(cuò)誤,如下:

game_functions:

import sys

import pygame

def check_events(ship):
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        elif event.type == pygame.KEYDOWN:
            if event.event == pygame.K_RIGHT:
                # ship.rect.centerx += 100
                ship.moving_right = True
            elif event.event == pygame.K_LEFT:
                ship.moving_left = True
        elif event.type == pygame.KEYUP:
            if event.event == pygame.K_RIGHT:
                ship.moving_right = False
            elif event.event == pygame.K_LEFT:
                ship.moving_left = False
def update_screen(ai_settings, screen, ship):
    screen.fill(ai_settings.bg_color)
    ship.blitme()
    pygame.display.flip()

錯(cuò)誤原因分析:

在pygame中,鍵盤(pán)是否按下監(jiān)聽(tīng)事件是通過(guò) event.type 事件;

而具體按鍵事件是要通過(guò) event.key事件;

并且在重構(gòu)ship類(lèi)代碼時(shí)也犯了錯(cuò)誤:

下面代碼時(shí)正確的,之前犯的錯(cuò)誤是在update()方法中,更新的仍是rect屬性,而不是新加的center屬性.

import pygame

class Ship():

    def __init__(self, ai_settings, screen):
        #初始化飛船位置
        self.screen = screen
        self.ai_settings = ai_settings

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

        self.rect.centerx = self.screen_rect.centerx
        self.rect.bottom = self.screen_rect.bottom

        self.center = float(self.rect.centerx)

        self.moving_right = False
        self.moving_left = False

    def update(self):
        if self.moving_right:
            self.center += self.ai_settings.ship_speed_factor
        elif self.moving_left:
            self.center -= self.ai_settings.ship_speed_factor
        self.rect.centerx = self.center

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