为什么画完后这些圆不消失？

Question

当我运行这个代码的时候，它只是做一个圆的轨迹，而不是一个圆在移动。代码如下：

import pygame, sys, random
from pygame.locals import *
pygame.init()
windowSurface = pygame.display.set_mode((500, 400), 0, 32)
WHITE = (255, 255, 255)

circX = 250 
circY= 250
diffX= 0
diffY=0

while True:
 for event in pygame.event.get():
  if event.type == QUIT:
   pygame.quit()
   sys.exit()
 diffX += random.randint(-1,1)
 diffY += random.randint(-1,1)
 circX += diffX
 circY += diffY
 circLocate = (circX,circY)
 pygame.draw.circle(windowSurface, WHITE, circLocate, 10, 0)
 pygame.display.flip()

Answer 1

每次你想让圆圈移动时，这个添加项都会清除你的屏幕

while True:
 for event in pygame.event.get():
  if event.type == QUIT:
   pygame.quit()
   sys.exit()
 windowSurface.fill(WHITE) //add this line to clear the screen
 diffX += random.randint(-1,1)
 diffY += random.randint(-1,1)
 circX += diffX
 circY += diffY
 circLocate = (circX,circY)
 pygame.draw.circle(windowSurface, WHITE, circLocate, 10, 0)
 pygame.display.flip()

Answer 2

你必须清除屏幕，让它看起来像是物体在移动。你知道吗

windowSurface.fill(WHITE)

因此：

import pygame, sys, random
from pygame.locals import *
pygame.init()
windowSurface = pygame.display.set_mode((500, 400), 0, 32)
WHITE = (255, 255, 255)

circX = 250 
circY= 250
diffX= 0
diffY=0

while True:
 for event in pygame.event.get():
  if event.type == QUIT:
   pygame.quit()
   sys.exit()
 diffX += random.randint(-1,1)
 diffY += random.randint(-1,1)
 circX += diffX
 circY += diffY
 circLocate = (circX,circY)
 windowSurface.fill(WHITE)
 pygame.draw.circle(windowSurface, WHITE, circLocate, 10, 0)
 pygame.display.flip()

但是，请确保windowSurface.fill()在pygame.draw.circle()之前是，否则，它将只显示一个白色屏幕。你知道吗