Spcomm 属性详解

http://wenku.baidu.com/link?url=w53wCrhi_E33atqp0joeG029YO3H2z4Xy101oGbKqhG9bfWJQHSmcMi4q7l6xrS424St3oVUzqxJ8d_hh6n_XZ1GCiTgGnqHaxSLqFr7_Wy