Sprite 元素未更新

Question

我正在尝试在 PYGAME 中对彩色单元格的动画进行编程，在每次迭代中，它们中的几个会交换各自的颜色。但是，我不太明白为什么，代码生成了单元格网格，但没有任何形式的移动。它只是保持静止。

import random
import pygame
import sys

colors = [(77,2,6),(180,5,180),(140,180,11)]

class CELL () :
    def __init__ (self,x,y,ide):
        self.color = random.choice(colors)
        self.ide = ide
        self.x = x
        self.y = y

n, m = 10, 10
block_width, block_height = 50, 50
win_width, win_height = block_width*m, block_height*n
# Matrix : 10x10
# Cell size : 50x50
# Window size : 500x500

cells = {}
for i in range(n):
    for j in range(m):
        cells[i*n+j] = CELL(i,j,i*n+j)
# We create a cells dictionary in which keys are the 
# ID attribute of each cell object stored.

class sprite_CELL (pygame.sprite.Sprite):
    def __init__ (self,cell_obj):
        pygame.sprite.Sprite.__init__(self)
        self.cell = cell_obj
        # Represents one of the cells.
        self.image = pygame.Surface([block_width,block_height])
        self.update_rect()
    def update_rect (self):
        self.image.fill(self.cell.color)
        self.rect = self.image.get_rect()
        # We update the rect according to the current color for the linked cell.
        self.rect.topleft = [self.cell.x*block_width, self.cell.y*block_height]

sprites_group = pygame.sprite.Group()
for cell in cells.values():
    sprites_group.add(sprite_CELL(cell))

# So far we have created a group of sprites containing sprites whose method
# "("update_rect" updates their graphical representation depending on the
# color of the cell to which the sprite is linked.

# API

pygame.init()
clock = pygame.time.Clock()
window = pygame.display.set_mode((win_width, win_height))

sprites_group.draw(window)

while True:

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

    rand_cell_a = random.choice(list(cells.values()))
    rand_cell_b = random.choice(list(cells.values()))
    # We randomly choose two cells.
    color_a = cells[rand_cell_a.ide].color
    color_b = cells[rand_cell_b.ide].color
    # We extract the colors and...
    cells[rand_cell_a.ide].color = color_b
    cells[rand_cell_b.ide].color = color_a
    # Swap the colors for the cells.

    sprites_group.update()
    # Updating the sprites should update their linked
    # colors too.

    pygame.display.flip()
    clock.tick(60)
    # And that's done iteratively.

如果有人能帮我解决这个问题，我将不胜感激。

Answer 1

您需要将update_rect 更改为update，然后您需要将sprites_group.draw(window) 放入循环中（在sprites_group.update() 之后和pygame.display.flip() 之前），程序就可以正常工作了。 精灵正在改变颜色，但您只在脚本开头绘制了一次，因此它们保持相同的颜色。

Answer 2

首先，您必须在每一帧中重新绘制研磨。您必须在应用程序循环中调用sprites_group.draw(window)：

while True:
    # [...]

    sprites_group.draw(window)           # <--- draw grid
    pygame.display.flip()
    clock.tick(60)

---

改变颜色属性是不够的。您还必须致电update_rect。因为你必须用新颜色（self.image.fill(self.cell.color)）填充图像：

cells[rand_cell_a.ide].color = color_b
cells[rand_cell_b.ide].color = color_a
for s in sprites_group:
    s.update_rect() 

---

但是，请参阅pygame.sprite.Group.update:

对组中的所有 Sprite 调用 update() 方法。

我建议将方法从update_rect 重命名为update：

class sprite_CELL (pygame.sprite.Sprite):
    def __init__ (self,cell_obj):
        pygame.sprite.Sprite.__init__(self)
        self.cell = cell_obj
        # Represents one of the cells.
        self.image = pygame.Surface([block_width,block_height])
        self.update()

    def update(self):
        self.image.fill(self.cell.color)
        self.rect = self.image.get_rect()
        # We update the rect according to the current color for the linked cell.
        self.rect.topleft = [self.cell.x*block_width, self.cell.y*block_height]

所以调用sprites_group.update()就足够了：

cells[rand_cell_a.ide].color = color_b
cells[rand_cell_b.ide].color = color_a
sprites_group.update()