pyglet：按下按鈕時更改sprite實例的圖像

Question

此代碼在黑色背景上顯示圖像assassin1.png。只要按下鍵，圖像就會向右移動，並在釋放鍵後立即停止移動。

只要我按下鍵，它也應該改爲圖像assassin2.png，當我釋放鍵時，它應該改回assassin1.png。 但是，此代碼在移動時從不顯示assassin2.png圖像。爲什麼這樣，我該如何解決這個問題？

import pyglet 

class Assassin(pyglet.sprite.Sprite): 
    def __init__(self, batch, img): 
     pyglet.sprite.Sprite.__init__(self, img, x = 50, y = 30) 

    def stand(self): 
     self.img = pyglet.image.load("assassin1.png") 
     return self 

    def move(self): 
     self.img = pyglet.image.load('assassin2.png')  
     return self 

class Game(pyglet.window.Window): 
    def __init__(self): 
     pyglet.window.Window.__init__(self, width = 315, height = 220) 
     self.batch_draw = pyglet.graphics.Batch() 
     self.player = Assassin(batch = self.batch_draw, img = pyglet.image.load("assassin1.png")) 
     self.keys_held = []  
     self.schedule = pyglet.clock.schedule_interval(func = self.update, interval = 1/60.) 

    def on_draw(self): 
     self.clear()   
     self.batch_draw.draw() 
     self.player.draw() 

    def on_key_press(self, symbol, modifiers): 
     self.keys_held.append(symbol) 
     if symbol == pyglet.window.key.RIGHT: 
      self.player = self.player.move() 
      print "The 'RIGHT' key was pressed" 

    def on_key_release(self, symbol, modifiers): 
     self.keys_held.pop(self.keys_held.index(symbol)) 
     self.player = self.player.stand() 
     print "The 'RIGHT' key was released" 

    def update(self, interval): 
     if pyglet.window.key.RIGHT in self.keys_held: 
      self.player.x += 50 * interval 

if __name__ == "__main__": 
    window = Game() 
    pyglet.app.run() 

Answer 1

我看着pyglet's source code，我認爲這個問題是在這裏：

self.img = pyglet.image.load(... 

的圖像存儲在self.image變量，而不是self.img。因此改爲：

self.image = pyglet.image.load(... 

應該更新精靈正在使用的圖像。