pygame 只是显示黑屏

Question

I'm trying to get this game to work but it just displays a black screen. its a simple game where you just avoid falling blocks. I've looked at related questions but none of the answers worked for me.it says i have to add more details so hopefully this line will be enough cuz idk what else to write in this line to add detail to my post. my code:

import pygame
import random
import sys
pygame.init()
WIDTH = 800
HEIGHT = 600

PLAYER_COLOR = (200,0,0)
ENEMY_COLOR = (0,200,0)
BACKGROUND_COLOR = (0,120,150)

player_size = 50

player_pos = [WIDTH/2, HEIGHT-2*player_size]

enemy_size = 50
enemy_pos = [random.randint(0,WIDTH-enemy_size),0]
enemy_list = [enemy_pos]

SPEED = 5
screen = pygame.display.set_mode((WIDTH,HEIGHT))

game_over = False

score = 0

clock = pygame.time.Clock

def drop_enemies(enemy_list):
    if len(enemy_list) < 10:
        x_pos = random.randint(0,WIDTH-enemy_size)
        y_pos = 0
        enemy_list.append([x_pos, y_pos])

def draw_enemies(enemy_list):
    for enemy_pos in enemy_list:
        pygame.draw.rect(screen, ENEMY_COLOR, (enemy_pos[0], enemy_pos[1], enemy_size, enemy_size))

def update_enemy_position(enemy_list, score):
    for idx, enemy_pos in enumerate(enemy_list):
        if enemy_pos[1] >= 0 and enemy_pos[1] < HEIGHT:
            enemy_pos[1] += SPEED
        else:
            enemy_list.pop(idx)
            score += 1
    return score

def collision_check(enemy_list, player_pos):
    for enemy_pos in enemy_list:
        return True
    return False




def detect_collision(player_pos, enemy_pos):
    p_x = player_pos[0]
    p_y = player_pos[1]

    e_x = enemy_pos[0]
    e_y = enemy_pos[1]

    if e_x >= p_x and e_x < (p_x + player_size) or p_x >= e_x and p_x < (e_x+enemy_size):
        if e_y >= p_y and e_y < (p_y + player_size) or p_y >= e_y and e_y < (e_y+enemy_size):
            return True
    return False

while not game_over:
    screen.fill(BACKGROUND_COLOR)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

        if event.type == pygame.KEYDOWN:
            x = player_pos[0]
            y = player_pos[1]

            if event.key == pygame.K_LEFT:
                x -= player_size
            elif event.key == pygame.K_RIGHT:
                x += player_size

            player_pos = [x,y]

    drop_enemies(enemy_list)
    update_enemy_position(enemy_list, score)
    if collision_check(enemy_list, player_pos):
        game_over = True
        break

    draw_enemies(enemy_list)
    pygame.draw.rect(screen, ENEMY_COLOR, (enemy_pos[0], enemy_pos[1], enemy_size, enemy_size))
    pygame.draw.rect(screen, PLAYER_COLOR, (player_pos[0], player_pos[1], player_size, player_size))
    clock.tick(30)
    pygame.display.update()

Answer 1

The problem is here:

def collision_check(enemy_list, player_pos):
    for enemy_pos in enemy_list:
        return True
    return False

You are missing the condition check inside the for that checks for/detects the collision between the enemy_pos and the players position. It is probably supposed to look like this:

def collision_check(enemy_list, player_pos):
    for enemy_pos in enemy_list:
        if detect_collision(player_pos, enemy_pos):
            return True
    return False

Right now it is always returning True and so your game is exiting before drawing anything, hence the black screen.

Edit:

I noticed there are also two additional fairly simple typo like bugs in the code. I was about to point them out as well. However something struck me about the nature of the bugs. This has the feel of an assignment: "Find the three bugs in this code and get it working". If this is really your code we are happy to help, but if this is a homework assignment, we are not helping you by doing it for you instead of you learning by doing it.

The previous bug was pretty easy to find and so are the remaining two. Give debugging the rest a try. I recommend using an IDE for debugging, not just running the script. There are many good free IDE's out there that can make you programming experience and particularly the debugging experience much easier.