本DLL应用场合广泛，比如车辆定位系统，路灯监控系统，这些都与地理信息有关。其实在一些需要图形界面，用户能在图形背景上自定义作图，并在该图形界面上进行操作的场合都能得到很好的应用。-wide applications, such as vehicle location system, street lamps monitoring systems, which are related to geographic information. In fact, some need a graphica