擅长:python、mysql、java
<p>创建一个类<code>Ball</code>。该类有3个属性。位置(<code>self.x</code>,<code>self.y</code>)和当前大小(<code>self.size</code>)。该调用必须调用方法<code>change_size</code>更改球的大小并<code>draw_ball</code>绘制球:</p>
<pre class="lang-py prettyprint-override"><code>class Ball:
def __init__(self):
self.x = random.randint(0,500)
self.y = random.randint(0,500)
self.size = 1
def change_size(self):
self.size += 1
if self.size > 100:
self.size = 1
def draw_ball(self, screen):
pygame.draw.circle(screen, YELLOW, (self.x, self.y), self.size)
</code></pre>
<p>创建<code>Ball</code>的实例,更改球的大小并在应用程序循环中绘制球:</p>
<pre class="lang-py prettyprint-override"><code>ball = Ball()
run_game = True
while run_game:
tickrate = clock.tick(FPS)
for event in pygame.event.get():
if event.type == pygame.QUIT:
quit()
screen.blit(background,background_rect)
ball.change_size()
ball.draw_ball(screen)
pygame.display.update()
</code></pre>