平缓运动

Question

我在main_screen上添加了一个对象/图像，这个对象称为cancer_cell。我在这里要做的是，我希望物体能平稳地移动。我必须重复按箭头键才能保持移动。如何使其移动while箭头键按下？

下面是代码：

exitgame = False
cellpos_x = 0
cellpos_y = cancer_cell.get_rect().height*2
while not exitgame:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            exitgame = True
            quitgame()
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                cellpos_x -= 10
            if event.key == pygame.K_RIGHT:
                cellpos_x += 10


    gameplay_bg = pygame.image.load("/Users/wolf/Desktop/python/img/gameplay_bg.png").convert()
    main_screen.fill(white)
    main_screen.blit(gameplay_bg, [0,0])
    main_screen.blit(cancer_cell, [cellpos_x, cellpos_y])
    pygame.display.flip()
    clock.tick(20)

有人告诉我在How to use pygame.KEYDOWN尝试这个解决方案:但这也不起作用。或者我做错了

if event.type == pygame.KEYDOWN:
    key_pressed = pygame.key.get_pressed()
    if key_pressed[pygame.K_LEFT]:
        cellpos_x -= 10
    if key_pressed[pygame.K_RIGHT]:
        cellpos_x += 10

Answer 1

问题求解

我解决了这个问题，只从FOR循环中去掉了这个部分，而不是退出游戏：

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            exitgame = True
            quitgame()

    key_pressed = pygame.key.get_pressed()
    if key_pressed[pygame.K_LEFT]:
        cellpos_x -= 10
    if key_pressed[pygame.K_RIGHT]:
        cellpos_x += 10

Answer 2

我看到您已经解决了缩进问题，下面是您示例的另一个版本：

import pygame

class Player(object):
    def __init__(self, img_path):
        self.image = pygame.image.load(img_path)
        self.x = 0
        self.y = self.image.get_rect().height*2

    def handle_keys(self):
        key = pygame.key.get_pressed()
        dist = 1
        if key[pygame.K_RIGHT]:
            self.x += dist
        elif key[pygame.K_LEFT]:
            self.x -= dist

    def draw(self, surface):
        surface.blit(self.image, (self.x, self.y))


pygame.init()
clock = pygame.time.Clock()
size = width, height = 1024, 768
speed = [2, 2]
white = 1, 1, 1
main_screen = pygame.display.set_mode(size)
gameplay_bg = pygame.image.load("background.jpg")
cancer_cell = Player("player.jpg")
running = False

while not running:
    event = pygame.event.poll()

    if event.type == pygame.QUIT:
        running = True

    main_screen.fill(white)
    main_screen.blit(gameplay_bg, [0, 0])

    cancer_cell.handle_keys()
    cancer_cell.draw(main_screen)

    pygame.display.flip()

    clock.tick(50)
    pygame.display.set_caption("fps: " + str(clock.get_fps()))

您需要调整图像的路径("background.jpg"，"player.jpg")，使用此版本，您不会在游戏事件循环中反复加载sprite，玩家的移动将是平稳的。