如何从OracleParameter对象获取值

using System;
using Oracle.DataAccess.Client;
using Oracle.DataAccess.Types;

class Program
{
    static void Main(string[] args)
    {
        // 创建一个OracleConnection对象
        OracleConnection conn = new OracleConnection("Data Source=myServer;User ID=myUser;Password=myPassword;");

        // 打开连接
        conn.Open();

        // 创建一个OracleCommand对象
        OracleCommand cmd = new OracleCommand("SELECT first_name, last_name FROM employees WHERE employee_id = :emp_id", conn);

        // 创建一个新的OracleParameter对象并添加到Parameters集合中
        OracleParameter param = new OracleParameter("emp_id", OracleDbType.Int32);
        param.Value = 123;
        cmd.Parameters.Add(param);

        // 执行查询
        OracleDataReader reader = cmd.ExecuteReader();

        // 读取查询结果
        while (reader.Read())
        {
            // 使用GetOracleValue方法从OracleParameter对象中获取值
            string firstName = reader.GetOracleValue(0).ToString();
            string lastName = reader.GetOracleValue(1).ToString();

            Console.WriteLine("First Name: " + firstName);
            Console.WriteLine("Last Name: " + lastName);
        }

        // 关闭连接
        conn.Close();
    }
}