Leap Motion 和 Pygame 中的文本显示

用户想要通过 Pygame 库与 Leap Motion 传感器配合使用，并在窗口中显示来自 Leap Motion 的数据。在尝试从 SampleListener 类中获取变量并将其提供给 Main 方法时，出现了“AttributeError: 'function' object has no attribute 'avg_pos'”错误。

2. 解决方案

错误消息表明 SampleListener.on_frame.avg_pos 不存在。这是因为 avg_pos 是 on_frame 方法内的局部变量，在方法外无法访问。

为了修复此错误，可以将 avg_pos 作为 SampleListener 类的属性，并在 on_frame 方法中对它进行更新。这样，avg_pos 就可以在 main 函数中访问。

以下是修改后的代码：

import Leap, sys, pygame

#Window 
windowWidth = 800
windowHeight = 600

#Leap Motion Settings
class SampleListener(Leap.Listener):

    def __init__(self):
        self.avg_pos = Leap.Vector()

    def on_init(self, controller):
        print "Initialized"

    def on_connect(self, controller):
        print "Connected"

    def on_disconnect(self, controller):
        # Note: not dispatched when running in a debugger.
        print "Disconnected"

    def on_exit(self, controller):
        print "Exited"

    def on_frame(self, controller):
        # Get the most recent frame and report some basic information
            if not self.frame.hands.empty:
                # Get the first hand
                hand = self.frame.hands[0]

                # Check if the hand has any fingers
                fingers = hand.fingers
                if not fingers.empty:
                    # Calculate the hand's average finger tip position
                    self.avg_pos = Leap.Vector()
                    for finger in fingers:
                        self.avg_pos += finger.tip_position
                    self.avg_pos /= len(fingers)
                    print "Hand has %d fingers, average finger tip position: %s" % (
                          len(fingers), self.avg_pos)

#Application Loop
def main():
    pygame.init()
    window = pygame.display.set_mode((windowWidth,windowHeight))
    pygame.display.set_caption("TEST123")

    #Surface 
    background = pygame.Surface(window.get_size())
    background = background.convert()
    background.fill ((50,0,80))

    if pygame.font:
        font = pygame.font.Font(None, 36)
        text = font.render("%s" % listener.avg_pos, 1, (255, 255, 255))
        textpos = text.get_rect(centerx=background.get_width()/2)
        background.blit(text, textpos)

    # Create a sample listener and controller
    listener = SampleListener()
    controller = Leap.Controller()

    # Have the sample listener receive events from the controller
    controller.add_listener(listener)

    clock = pygame.time.Clock()

    while True:
        clock.tick(60)
        #Handle Input Events
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                sys.exit()
                # Remove the sample listener when done
                controller.remove_listener(listener)

        window.blit(background, (0,0))
        pygame.display.flip()

if __name__ == "__main__":
    main()

现在，应该可以成功在窗口中显示来自 Leap Motion 的数据。