Method clear

js/managers/EventManager.js:124–129

* 清空所有事件监听

()

   * 清空所有事件监听
   */
  clear() {
    for (const { target, event, handler, options } of this.listeners.values()) {
      target.removeEventListener(event, handler, options);
    }
    this.listeners.clear();
  }

  /**
   * 获取监听器的唯一键