我遇到此类问题，一般是右键计算机－管理－服务，找到OracleOraDB12Home1TNSListener设为自动启动，并重启，当然这种操作你要确定监听文件什么的都已经检查无问题哦。
附上12c监听等文件，安装盘:\app\oracle\product\12.2.0\dbhome_1\network\admin下tnsnames.ora

ORACLR_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521)(Key = EXTPROC))
    )
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
      (PRESENTATION = RO)
    )
  )

安装盘:\app\oracle\product\12.2.0\dbhome_1\network\admin下sqlnet.ora
SQLNET.AUTHENTICATION_SERVICES= (NTS)
SQLNET.ALLOWED_LOGON_VERSION=8
NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)

安装盘:\app\oracle\product\12.2.0\dbhome_1\network\admin下listner.ora
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      #(PROGRAM = extproc)
      (ENVS = "EXTPROC_DLLS=ONLY:F:\app\oracle\product\12.2.0\dbhome_1\bin\oraclr12.dll")
      (SID_NAME = orcl)
      (ORACLE_HOME = F:\app\oracle\product\12.2.0\dbhome_1)
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
     (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))
    )
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = orcl))
    )
  )

ADR_BASE_LISTENER = F:\app\oracle\product\12.2.0\dbhome_1\log