pygame 中没有 pygame.display 初始化错误无法转换

Question

我正在使用 pygame 为我大学的一个项目制作游戏。我现在要做的就是创建一个球，当用户按下左右箭头键时，可以控制它在屏幕上来回移动。老实说，我真的不知道我在做什么，所以我使用 pygame 文档中用于 pong 作为我游戏基础的代码。我的代码在下面，如果有人知道我为什么会收到标题中的错误，请告诉我。

try:
        import sys
        import random
        import math
        import os
        import getopt
        import pygame
        from socket import *
        from pygame.locals import *
except ImportError, err:
        print "couldn't load module. %s" % (err)
        sys.exit(2)

def load_png(name):
    """ Load image and return image object"""
    fullname = name
    try:
        image = pygame.image.load(fullname)
        if image.get_alpha() is None:
            image = image.convert()
        else:
            image = image.convert_alpha()
    except pygame.error, message:
            print 'Cannot load image:', fullname
            raise SystemExit, message
    return image, image.get_rect()

class Ball(pygame.sprite.Sprite):
    def __init__(self, (xy)):
        pygame.sprite.Sprite.__init__(self)
        self.image, self.rect = load_png('ball.png')
        screen = pygame.display.get_surface()
        self.area = screen.get_rect()
        self.hit = 0
        self.speed = 10
        self.state = "still"

    def reinit(self):
        self.state = "still"
        self.movepos = [0,0]
        if self.side == "left":
            self.rect.midleft = self.area.midleft

    def update(self):
        newpos = self.rect.move(self.movepos)
        if self.area.contains(newpos):
            self.rect = newpos
        pygame.event.pump()

    def moveleft(self):
        self.movepos[1] = self.movepos[1] - (self.speed)
        self.state = "moveleft"

    def moveright(self):
        self.movepos[1] = self.movepos[1] + (self.speed)
        self.state = "moveright"

def main():
    running = True
    pygame.init()
    (width, height) = (800, 600)
    screen = pygame.display.set_mode((width, height))

    # Fill background
    background = pygame.Surface(screen.get_size())
    background = background.convert()
    background.fill((0, 0, 0))
    screen.blit(background, (0, 0))
    pygame.display.flip()


    global player
    player = Ball("left")
    playersprite = pygame.sprite.RenderPlain(player)

    playersprite.draw(screen)
    player.update()
    while running:

        for event in pygame.event.get():
            if event.type == KEYDOWN:
                if event.key == K_q:
                    running = False
                if event.key == K_LEFT:
                    player.moveleft()
                if event.key == K_RIGHT:
                    player.moveright()
            elif event.type == KEYUP:
                if event.key == K_UP or event.key == K_DOWN:
                    player.movepos = [0,0]
                    player.state = "still"
        #screen.blit(background, ball.rect, ball.rect)
        screen.blit(background, player.rect, player.rect)
        #screen.blit(background, player2.rect, player2.rect)
        #ballsprite.update()
        playersprite.update()
        #ballsprite.draw(screen)
        playersprite.draw(screen)



if __name__ == '__main__': main()

Answer 1

你的 python/pygame 是什么版本运行当我用 python 3.4 测试你的代码时，我首先在你的 try: except 语句中遇到语法错误，但这可能是由于不同版本的语法不同。解决这个问题后，我运行遇到了 movepos 按左键或右键时未定义的问题。将 self.movepos = [0, 0] 添加到 Ball class 的 __init__() 修复了这个问题。

我从来没有运行遇到您描述的错误，但是无论我做什么，游戏都会一直黑屏。

我想说的是，错误有时可能是由代码中较早的其他错误引起的，这些错误没有被提取出来。这里的答案之一很好地总结了它：error: video system not initialized; Is there a solution?

另外，什么变量存储球的 x 和 y 位置？我似乎无法弄清楚你是如何控制它的？

Answer 2

All I'm trying to get done right now is create a ball that can be controlled to go back and forth on the screen when the user presses the left and right arrow keys.

你太复杂了，你不需要 102 行来移动一个球。我写了一个简单的例子并发表了评论，我认为它可以帮助你很多。您真正需要做的就是检测按键，然后更新 x 和 y 变量，然后使用 x 和 y 变量绘制图像。

import pygame

screen_width = 1280
screen_height = 720

pygame.init()
screen = pygame.display.set_mode((screen_width,screen_height))

BLACK = (0,0,0)

ballImg = pygame.image.load("ball.jpg")
ballPosition = [0,0]
speed = 1


def game_loop():
    while 1:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                exit()

        #get all the keys being pressed
        keys = pygame.key.get_pressed()


        #depending on what key the user presses, update ball x and y position accordingly
        if keys[pygame.K_UP]:
            ballPosition[1] -= speed
        if keys[pygame.K_DOWN]:
            ballPosition[1] += speed
        if keys[pygame.K_LEFT]:
            ballPosition[0] -= speed
        if keys[pygame.K_RIGHT]:
            ballPosition[0] += speed


        screen.fill(BLACK) #fill the screen with black
        screen.blit(ballImg, ballPosition) #draw the ball
        pygame.display.update() #update the screen

game_loop()

pygame 中没有 pygame.display 初始化错误无法转换

cannot convert without pygame.display initialized error in pygame

python

pygame

display