python - 如何让敌人出现？

Question

当游戏第一次开始时，玩家和敌人都会出现，但当玩家移动时，敌人就会消失。

import pygame
import os 
import random 
from pygame.locals import * # Constants
import math
import sys
import random

pygame.init()  

screen=pygame.display.set_mode((1280,720)) #(length,height)
screen_rect=screen.get_rect()
background = pygame.Surface(screen.get_size())
background.fill((255,255,255))     # fill the background white 
White = (255,255,255)

screen.blit(background, (0, 0))

class Player(pygame.sprite.Sprite):

def __init__(self):

    self.rect = pygame.draw.rect(screen, (0,0,128), (50,560,50,25)) #(colour)(x-position,y-position,width,height)
    self.dist = 100

def draw_rect(self,x,y):    # This is my code which should make the player move
    screen.blit(background, (0, 0)) #If this isn't included then when the rectangle moves it's old positon will still be on the screen
    self.rect = self.rect.move(x*self.dist, y*self.dist); pygame.draw.rect(screen, (0, 0, 128), self.rect)
    pygame.display.update()

def handle_keys(self): # code to make the character move when the arrow keys are pressed
    keys = pygame.key.get_pressed()
    if keys[K_LEFT]:
        self.draw_rect(-0.05,0)
    elif keys[K_RIGHT]:
        self.draw_rect(0.05,0)
    elif keys[K_UP]:
        self.draw_rect(0,-0.05)
    elif keys[K_DOWN]:
        self.draw_rect(0,0.05)
    elif keys[K_SPACE]:
        self.draw_rect(0.4,-0.9)
    if self.rect.right > 1280:   # These are to stop the player from going out of the boundary
        self.rect.right = 1280
    if self.rect.left < 0:
        self.rect.left = 0
    if self.rect.bottom > 720:
        self.rect.bottom = 720
    if self.rect.top < 0:
        self.rect.top = 0

玩家的移动效果非常好。

class Enemy(pygame.sprite.Sprite): # the enemy class which works fine
def __init__(self):
    x = random.randint(50,450)
    self.rect = pygame.draw.rect(screen, (128,0,0), (300,x,50,25))

敌人只是在随机位置生成，并且当玩家四处移动时仍然应该出现。我尝试做一些事情，但没有成功。

clock = pygame.time.Clock()  # A clock to limit the frame rate.
player = Player()
enemy = Enemy()

def main():  #my main loop 
    running = True
    while running:
        player.handle_keys()
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
        clock.tick(60)  # Limit the frame rate to 60 FPS.
        pygame.display.flip()   #updates the whole screen

    if __name__ == '__main__': main()

Answer 1

这是因为你只绘制了一次敌人的Rect:在Enemy的__init__函数中。此外，您还可以在 Player 类的不同位置进行大量绘图，例如清除屏幕。别再这样做了。

您已经子类化 Sprite ，因此请按预期使用此类。 Sprite 有一个 image 和 rect 来定义它们的外观和位置，您可以将它们添加到 Group 中。它负责调用它们的 update 函数并将它们绘制到屏幕上。

您的代码应如下所示:

import pygame
import random 
from pygame.locals import * # Constants

pygame.init()  

screen=pygame.display.set_mode((1280,720)) #(length,height)
screen_rect=screen.get_rect()
background = pygame.Surface(screen.get_size())
background.fill((255,255,255))     # fill the background white 

class Player(pygame.sprite.Sprite):

    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((50,25))
        self.image.fill((0,0,128))
        self.rect = self.image.get_rect(topleft=(50,560))
        self.dist = 100

    def update(self): # code to make the character move when the arrow keys are pressed

        keys = pygame.key.get_pressed()
        if keys[K_LEFT]:
            self.rect.move_ip(-1,0)
        elif keys[K_RIGHT]:
            self.rect.move_ip(1,0)
        elif keys[K_UP]:
            self.rect.move_ip(0,-1)
        elif keys[K_DOWN]:
            self.rect.move_ip(0,1)
        self.rect.clamp_ip(screen_rect)

class Enemy(pygame.sprite.Sprite): # the enemy class which works fine
    def __init__(self):
        super().__init__()
        x = random.randint(50,450)
        self.image = pygame.Surface((50,25))
        self.image.fill((128,0,0))
        self.rect = self.image.get_rect(topleft=(300, x))

clock = pygame.time.Clock()  # A clock to limit the frame rate.
player = Player()
enemy = Enemy()
sprites = pygame.sprite.Group(player, enemy)

def main():  #my main loop 
    running = True
    while running:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
        sprites.update()
        screen.blit(background, (0, 0))
        sprites.draw(screen)
        clock.tick(60)  # Limit the frame rate to 60 FPS.
        pygame.display.flip()   #updates the whole screen

if __name__ == '__main__': 
    main()