Python Kivy - 如何对多次按键使用react？

Question

所以我读了这篇文章: How to handle several keys pressed at the same time in Kivy?

我根据 Kivy 网站 ( http://kivy.org/docs/tutorials/pong.html ) 上的教程实现了 Pong 游戏。 我的 PongGame Widget 有以下方法:

def __init__(self):
    super(PongGame, self).__init__()
    self._keyboard = Window.request_keyboard(self._keyboard_closed, self)
    self._keyboard.bind(on_key_down = self._on_keyboard_down)
    self._keyboard.bind(on_key_up = self._on_keyboard_up)

def _keyboard_closed (self):
    self._keyboard.unbind(on_key_down=self._on_keyboard_down)
    self._keyboard = None

def _on_keyboard_down (self, keyboard, keycode, text, modifiers):
    print('### ----------------------------------- ###')
    print('The keys', keycode, 'have been pressed down')
    print('You pressed the key', keycode[1], '.', sep=' ', end='\n')
    #print(' - text is %r' % text)
    print(' - modifiers are %r' % modifiers)

    if keycode[1] == 'w':
        if self.player1.center_y + 20 < self.height-85:
            self.player1.center_y += 20
    elif keycode[1] == 's':
        self.player1.center_y -= 20
    elif keycode[1] == 'up':
        self.player2.center_y += 20
    elif keycode[1] == 'down':
        self.player2.center_y -= 20

    return True
"""
def _on_keyboard_up (self, keyboard, keycode, text, modifiers):
    print('### ----------------------------------- ###')
    print('The keys', keycode, 'have been released.')
    print('You pressed the key', keycode[1], '.', sep=' ', end='\n')
    #print(' - text is %r' % text)
    print(' - modifiers are %r' % modifiers)

    return True
"""

def _on_keyboard_up(self, *args):
    print('up', args)

这样我就可以使用“w”、“s”、“up”和“down”来控制两个玩家。但是，仅执行最后按下的按钮的操作。这是一个问题，因为当其他玩家想要移动他们的桨时，玩家可能会通过一直按下按钮来干扰彼此的输入。

我该如何实现，让两个玩家同时控制，这样他们就不会互相妨碍，除非键盘不能再按下任何按键(硬件限制)？

我目前想用Kivy开发桌面游戏，而不是智能手机游戏，所以我想用真正的键盘来控制角色。

Answer 1

我的解决方案非常相似，但更短。 这是使用 set() 作为事件按钮列表的简单示例。

因此，如果您不想在我的解决方案中添加另一个操作，您只需以“button_character”格式向 self.pressed_actions 字典添加条目:lambda 函数，该函数将使用参数运行您的函数。

此示例将向控制台提示哪些按钮在每一帧中处于事件状态。

放心使用。

*set 就像一个列表，但不重复。所以您不必担心同一按钮的更多条目。

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.core.window import Window
from kivy.clock import Clock

class Basic(Widget):

    pFrame = 0

    def __init__(self, **kwargs):
        super(Basic, self).__init__(**kwargs)
        self._keyboard = Window.request_keyboard(self._keyboard_closed, self)
        self._keyboard.bind(on_key_down=self._on_keyboard_down)
        self._keyboard.bind(on_key_up=self._on_keyboard_up)

        self.pressed_keys = set()

        self.pressed_actions = {
            'w': lambda: self.text_example('w pressed'),
            's': lambda: self.text_example('s pressed'),
            'a': lambda: self.text_example('a pressed'),
            'd': lambda: self.text_example('d pressed'),
        }

    def _keyboard_closed(self):
        self._keyboard.unbind(on_key_down=self._on_keyboard_down)
        self._keyboard.unbind(on_key_up=self._on_keyboard_down)
        self._keyboard = None

    def _on_keyboard_down(self, keyboard, keycode, text, modifiers):
        self.pressed_keys.add(keycode[1])

    def _on_keyboard_up(self, keyboard, keycode):
        self.pressed_keys.remove(keycode[1])

    def text_example(self, text):
        print('Frame: %s Key %s' % (self.pFrame, text))

    def update(self, dt):
        for key in self.pressed_keys:
            try:
                self.pressed_actions[key]()
            except KeyError:
                print("Frame: %s Key %s. Omitted" % (self.pFrame, key))

        self.pFrame += 1

class MyApp(App):

    def build(self):    
        basic = Basic() 
        Clock.schedule_interval(basic.update, 1.0 / 2.0)
        return basic

if __name__ == '__main__':
    try:
        MyApp().run()
    except KeyboardInterrupt:
        print('App has been closed by ^C')