说明：  Qt5实现的系统虚拟键盘组件，可以方便地嵌入到各应用程序的登录框、密码输入框等地方，显示式样可以通过QSS文件来进行自定义。
(Qt5 system to achieve the virtual keyboard components, can be easily embedded into the application of the login box, password input box and other places, display style can be customized through the QSS file.)