为什么我的运动代码不起作用？

Question

I am trying to make a character move around. My problem is that when I run the program it immediately stops responding so I don't even know what the problem is. Here is my code.

import pygame, sys
from pygame.locals import*

pygame.init()
DISPLAYSURF = pygame.display.set_mode((780, 500), 0, 32)

FPS = 30
fpsClock = pygame.time.Clock()

sprite = pygame.image.load('CharacterFront.png')
spritex = 50
spritey = 50
charLeft = False
charRight = False
charUp = False
charDown = False

while True:

DISPLAYSURF.blit(sprite,(spritex,spritey))

for event in pygame.event.get():
    if event.type==QUIT:
        pygame.quit()
        sys.exit()

    if event.type == KEYDOWN:
        if (event.key == K_LEFT):
            charLeft = True
        elif (event.key == K_d):
            charRight = True
        elif (event.key == K_w):
            charUp = True
        elif (event.key == K_s):
            charDown = True
    if event.type == KEYUP:
        if (event.key == K_LEFT):
            charLeft = False
        elif (event.key == K_d):
            charRight = False
        elif (event.key == K_w):
            charUp = False
        elif (event.key == K_s):
            charDown = False

while charLeft == True:
    spritex -= 10
    sprite=pygame.image.load('CharacterLeft.png')
while charRight == True:
    spritex += 10
    sprite=pygame.image.load('CharacterRight.png')
while charUp == True:
    spritey -= 10
    sprite=pygame.image.load('CharacterBack.png')
while charDown == True:
    spritey += 10
    sprite=pygame.image.load('CharacterFront.png')


pygame.display.update()
fpsClock.tick(FPS)

I have already tried many different ways to do this but the closest I got caused the character to get pasted over and over and I had to spam the directions to actually move more than 10 pixels.

Answer 1

Your while char.. loops never end. You are already looping ( while True: at the top). Just make one move (eg spritey -= 10 ) and allow the outer loop to keep running.

For ideas on how to keep your character moving while a key is held, see this question .

Answer 2

Apart from what jonrsharpe said, you should not load the sprite every time a keypress is done. Instead load all your images before, and just blit them when necessary.

So your code will look like this:

sprite_back = pygame.image.load('CharacterBack.png')
sprite_front = pygame.image.load('CharacterFront.png')
sprite_right = pygame.image.load('CharacterRight.png')
sprite_left = pygame.image.load('CharacterLeft.png')

sprite = sprite_front

while True:

    DISPLAYSURF.blit(sprite,(spritex,spritey))

    if charLeft == True:
        spritex -= 10
    elif charRight == True:
        spritex += 10
    elif charUp == True:
        spritey -= 10
    elif charDown == True:
        spritey += 10

    for event in pygame.event.get():
        if event.type==QUIT:
            pygame.quit()
            sys.exit()

        if event.type == KEYDOWN:
            if (event.key == K_LEFT):
                charLeft = True
                sprite=sprite_left
            elif (event.key == K_d):
                charRight = True
                sprite=sprite_right
            elif (event.key == K_w):
                charUp = True
                sprite=sprite_back
            elif (event.key == K_s):
                charDown = True
                sprite=sprite_front
        if event.type == KEYUP:
            if (event.key == K_LEFT):
                charLeft = False
            elif (event.key == K_d):
                charRight = False
            elif (event.key == K_w):
                charUp = False
            elif (event.key == K_s):
                charDown = False