实现简单的绘图功能，类似cass系统，能将所会图形，保存为txt格式，并将txt数据重新导入，实现绘图 -Simple graphics, like cass system, which can be graphics, saved as a txt format, and re-import the txt data to achieve graphics

将南方CASS产生的cas交换格式文件导入Arcgis数据库。-input south cass file(AutoCad) to Arcgis (ArcSDE)