net manager连接不成功。在命令框中输入tnsping DB1(自己建立的数据库)，发现超时，解析适配器不能解析字段，或者是host不等于本地地址。

  cmd打开命令窗口，输入lsnrctl,然后输入start，开启监听程序。重新连接仍然超时。

  可能是tnsnames.ora、sqlnet.ora、listener.ora出错。

tnsnames.ora内容：

# tnsnames.ora Network Configuration File: D:\oracle\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.

DB1 =                            
  (DESCRIPTION =
    (ADDRESS_LIST =             
      (ADDRESS = (PROTOCOL = TCP)(HOST = HUNDSUN-EAE3572.hs.handsome.com.cn)(PORT = 1521))
    )                 
    (CONNECT_DATA =
      (SERVICE_NAME = DB1)          
    )
  )

listener.ora原文：

# listener.ora Network Configuration File: D:\oracle\network\admin\listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = D:\oracle)
      (PROGRAM = extproc)
    )
  )
(SID_DESC = 
    (GLOBAL_DBNAME = ORA) 
    (ORACLE_HOME = D:\oracle)    //*************oracle_home，oracle的安装目录
    (SID_NAME = DB1)            //************sid_name，数据库名称
    )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = TCP)(HOST = HUNDSUN-EAE3572.hs.handsome.com.cn)(PORT = 1521))
      )                          //*********address,等同于tnsnames.ora中的
    )
  )