如何在Kivy中处理多键盘输入实现平台游戏同时移动与跳跃

你的代码存在两个核心问题，导致无法同时触发移动和跳跃：

1. 按键事件逻辑存在缺陷

• 你通过事件触发的方式执行移动逻辑，仅在按键按下的瞬间执行一次移动操作，无法支持长按持续移动
• 左右按键的判断混用了if和elif，且没有维护全局的按键状态表，无法同时识别多个按键的按下状态
• 你定义的key_state是全局变量，按键松开时的赋值仅作用于函数局部作用域，逻辑完全不生效

2. 移动逻辑的执行时机错误
   角色的持续移动应该放在帧更新循环中执行，而不是绑定在按键按下事件上

修复方案 #

步骤1：修改Main.py中的LevelOne类

首先在__init__方法中新增按键状态存储，同时新增帧更新的移动调度逻辑：

class LevelOne(MDScreen):
    from PlayerAction import _keyboard_closed, _on_keyboard_down, _on_keyboard_up
    gravity_force = 1800

    def __init__(self, **kwargs):
        super().__init__(**kwargs)    
        # 新增：存储当前按下的按键状态
        self.pressed_keys = set()
        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)
        Clock.schedule_once(self.setup, 1/60)

    def setup(self, dt):
        self.player_image = PlayerImage()
        self.add_widget(self.player_image)
        Clock.schedule_interval(self.game_gravity, 1/30)
        # 新增：每帧更新角色移动状态
        Clock.schedule_interval(self.update_movement, 1/30)
    
    # 新增：每帧根据按键状态执行移动
    def update_movement(self, dt):
        if "left" in self.pressed_keys:
            self.player_image.move_left(True)
        if "right" in self.pressed_keys:
            self.player_image.move_right(True)

    # 原有game_gravity方法保持不变
    def game_gravity(self, dt):
        if self.player_image.on_air:
            self.player_image.player_gravity_vel -= self.gravity_force * 1/30
            self.player_image.y += self.player_image.player_gravity_vel * 1/30 
        if self.player_image.y <= 60:
            self.player_image.y = 60
            self.player_image.player_gravity_vel = 0
            self.player_image.on_air = False

步骤2：重写PlayerAction.py的全部逻辑

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

def _on_keyboard_down(self, keyboard, keycode, *args):
    key = keycode[1]
    # 将按下的按键存入状态集合
    if key in ("up", "left", "right"):
        self.pressed_keys.add(key)
    # 跳跃仅在按下瞬间触发
    if key == "up":
        self.player_image.jump(True)
    return True

def _on_keyboard_up(self, keyboard, keycode, *args):
    key = keycode[1]
    # 将松开的按键从状态集合移除
    if key in self.pressed_keys:
        self.pressed_keys.remove(key)
    return True

修改完成后，按住方向键的同时按下跳跃键，就会每帧同时执行移动和重力更新，实现预期的向前跳跃效果。

内容的提问来源于stack exchange，提问作者Stoicism