C/S三层结构SocketConn: TSocketConnection;
中间层application 关闭或意外关机，客户端就不关闭程序了 提示：RPC服务器不可用
关闭中间层提示：
com server warning
there are still active com objects in this application one or more clients may have references to these objects so manually closing this application may cause those client application to fail .
are you sure you want to close this application
