pygame 为什么飞船只能左右移动不能上下移？

Question

import pygame
import sys

def run_game():
    pygame.init()
    screen=pygame.display.set_mode((1200,600))
    pygame.display.set_caption("game over")


    image=pygame.image.load('selfimages/airplane.bmp')
    rect=image.get_rect()
    screen_rect=screen.get_rect()

    rect.centerx=screen_rect.centerx
    rect.centery=screen_rect.centery
    xcenter=float(rect.centerx)
    ycenter=float(rect.centery)

    moving_right=False
    moving_left=False
    moving_down=False
    moving_up=False

    while True:
        for event in pygame.event.get():
            if event.type==pygame.QUIT:
                sys.exit()
            elif event.type==pygame.KEYDOWN:
                if event.key==pygame.K_RIGHT:
                    moving_right=True

                elif event.key==pygame.K_LEFT:
                    moving_left=True

                elif event.key==pygame.K_UP:
                    moving_up=True

                elif event.key==pygame.K_DOWN:
                    moving_dowm=True
            elif event.type==pygame.KEYUP:
                if event.key==pygame.K_RIGHT:
                    moving_right=False

                elif event.key==pygame.K_LEFT:
                    moving_left=False

                elif event.key==pygame.K_UP:
                    moving_up=False

                elif event.key==pygame.K_DOWN:
                    moving_dowm=False

        if moving_right and rect.right<screen_rect.right:
            xcenter+=1.5
        if moving_left and rect.left>0:
            xcenter-=1.5
        if moving_up and rect.top<screen_rect.top:
            ycenter+=1.5
        if moving_down and rect.bottom>0:
            ycenter-=1.5

        rect.centerx=xcenter
        rect.centery=ycenter

        screen.fill((255,255,255))
        screen.blit(image,rect)
        pygame.display.flip()


run_game()

麻烦帮我看看问题出在哪，谢谢大家

Answer 1

import pygame
import sys

def run_game():
pygame.init()
screen=pygame.display.set_mode((1000,700))
pygame.display.set_caption("game over")

image=pygame.image.load('images/ship1.bmp')
rect=image.get_rect()
screen_rect=screen.get_rect()

rect.centerx=screen_rect.centerx
rect.centery=screen_rect.centery
xcenter=float(rect.centerx)
ycenter=float(rect.centery)

moving_right=False
moving_left=False
moving_down=False
moving_up=False

while True:
    for event in pygame.event.get():
        if event.type==pygame.QUIT:
            sys.exit()
        elif event.type==pygame.KEYDOWN:
            if event.key==pygame.K_RIGHT:
                moving_right=True

            elif event.key==pygame.K_LEFT:
                moving_left=True

            elif event.key==pygame.K_UP:
                moving_up=True

            elif event.key==pygame.K_DOWN:
                moving_down=True
                
        elif event.type==pygame.KEYUP:
            if event.key==pygame.K_RIGHT:
                moving_right=False

            elif event.key==pygame.K_LEFT:
                moving_left=False

            elif event.key==pygame.K_UP:
                moving_up=False

            elif event.key==pygame.K_DOWN:
                moving_down=False

    if moving_right and rect.right<screen_rect.right:
        xcenter+=0.5
    if moving_left and rect.left>0:
        xcenter-=0.5
    if moving_up and rect.top>0:
        ycenter-=0.5
    if moving_down and rect.bottom>screen_rect.top:
        ycenter+=0.5

    rect.centerx=xcenter
    rect.centery=ycenter

    screen.fill((255,255,255))
    screen.blit(image,rect)
    pygame.display.flip()

run_game()