该项目进行button类的重绘工作，与普通控件不同的是button的重绘工作不能由OnCtrlColor中返回画刷实现，要通过派生新累重写DrawItem来实现。-The project button redraw the common control, the button redraw work can not be returned by the OnCtrlColor brush to achieve, to be achieved by deriving new tired rewri