命令处理类，包括接口类和抽象类的定义，用于大型系统中菜单、按钮等动作对象的绑定类，代码来自于项目实践，具有复用性。-Command processing categories, including the definition of the interface classes and abstract classes for the binding of the large system menus, buttons, actions such as object class code from the project practice, reusability.