MicroStation开发语言（MDL）应用教程，MDL是MicroStation的“应用引擎”，可以直接在MicroStation中运行，并且表现为MicroStation本身的一部分。-MicroStation Development Language (MDL) application tutorial, MDL is MicroStation' s " application"　engine, can run in MicroStation and MicroStation itself as part of the performance.