convert_alpha不生效

qhlouc

1. import pygame
   
2. import sys
   
3. from pygame.locals import *
   
4. from random import *
   
5. 
   
6. class Ball(pygame.sprite.Sprite):
   
7.     def __init__(self, image, pos, speed, bg_size):
   
8.         pygame.sprite.Sprite.__init__(self)
   
9. 
   
10.         self.image = pygame.image.load(image).convert_alpha()
    
11.         self.rect = self.image.get_rect()
    
12.         self.rect.left, self.rect.top = pos
    
13.         self.speed = speed
    
14.         self.bg_width, self.bg_height = bg_size[0], bg_size[1]
    
15. 
    
16.     def move(self):
    
17.         self.rect = self.rect.move(self.speed)
    
18. 
    
19.         if self.rect.right < 0:
    
20.             self.rect.left = self.bg_width    # 穿越
    
21.         elif self.rect.left > self.bg_width:
    
22.             self.rect.right = 0
    
23.         elif self.rect.bottom < 0:
    
24.             self.rect.top = self.bg_height
    
25.         elif self.rect.top > self.bg_height:
    
26.             self.rect.bottom = 0
    
27. 
    
28. def main():
    
29.     pygame.init()
    
30. 
    
31.     ball_image = "gray_ball.png"
    
32.     bg_image = "background.png"
    
33. 
    
34.     running = True
    
35. 
    
36.     bg_size = width, height = 1024, 681
    
37.     radius = 100
    
38.     clock = pygame.time.Clock()
    
39. 
    
40.     screen = pygame.display.set_mode(bg_size)
    
41.     pygame.display.set_caption("Play the ball")
    
42. 
    
43.     background = pygame.image.load(bg_image).convert_alpha()
    
44. 
    
45.     balls = []
    
46.     for i in range(5):
    
47.         pos = randint(0, width - radius), randint(0, height - radius)
    
48.         speed = [randint(-10, 10), randint(-10, 10)]
    
49.         ball = Ball(ball_image, pos, speed, bg_size)
    
50.         balls.append(ball)
    
51. 
    
52.     while running:
    
53.         for event in pygame.event.get():
    
54.             if event.type == QUIT:
    
55.                 sys.exit()
    
56.         
    
57.         screen.blit(background, (0, 0))
    
58. 
    
59.         for ball in balls:
    
60.             ball.move()
    
61.             screen.blit(ball.image, ball.rect)
    
62. 
    
63.         pygame.display.flip()
    
64.         clock.tick(30)
    
65. 
    
66. 
    
67. if __name__ == "__main__":
    
68.     main()

复制代码

在学习小甲鱼的python入门课程，ball图片已经使用convert_alpha转换，但出来的效果仍然有黑色背景边框。
请大家帮忙看看是哪里出了问题？

低调的恶棍

兄弟，我花了两个小时终于解决了这个问题，需要用ps把图片的背景去掉并转化为png格式才能用