c++ builder实现的自定义样式的滚动条，因为自定义滚动条的实现比其他控件难度大，所以对于喜欢研究界面编程的朋友有很大的帮助-c++ builder to achieve a custom style of scroll bars, since the realization of the definition of a scroll bar is difficult to control than others, so research like interface for progra