c#连接ORACLE报错ORA-12154: TNS: 无法处理服务名


string ConnectionString = "Data Source=ORCL; User Id=sjwj; Password=sjwj";  //连接字符串          
            OracleConnection conn = new OracleConnection(ConnectionString);    //创建一个新连接                
            try {                 
                conn.Open();    //打开连接              
               
            }
            catch (Exception ex)
            {                MessageBox.Show(ex.Message.ToString());
            }
            finally
            {
                conn.Close();
            }连不上
ORCL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )
连接串也配置好了  PLsql能连上  就C#连接ORACLE连不上