[C#/WCF] 서비스 계약 인터페이스 상속하기

using System;
using System.Collections;
using System.ServiceModel;

namespace TestProject
{
    /// <summary>
    /// 상점 인터페이스
    /// </summary>
    [ServiceContract(Namespace="http://company.com/bookstore")]
    public interface IBookStore
    {
        //////////////////////////////////////////////////////////////////////////////////////////////////// Method

        #region 주문하기 - Order(userID, isbn, amount)

        /// <summary>
        /// 주문하기
        /// </summary>
        /// <param name="userID">사용자 ID</param>
        /// <param name="isbn">ISBN</param>
        /// <param name="amount">수량</param>
        /// <returns>주문 ID</returns>
        [OperationContract]
        int Order(string userID, string isbn, int amount);

        #endregion

        #region 취소하기 - Cancel(orderID)

        /// <summary>
        /// 취소하기
        /// </summary>
        /// <param name="orderID">주문 ID</param>
        /// <returns>처리 결과</returns>
        [OperationContract]
        bool Cancel(int orderID);

        #endregion

        #region 검색하기 - Search(title)

        /// <summary>
        /// 검색하기
        /// </summary>
        /// <param name="title">제목</param>
        /// <returns>제목 배열</returns>
        [OperationContract]
        string[] Search(string title);

        #endregion
    }

    /// <summary>
    /// 상점 2 인터페이스
    /// </summary>
    [ServiceContract(Namespace="http://company.com/bookstore2")]
    public interface IBookStore2 : IBookStore
    {
        //////////////////////////////////////////////////////////////////////////////////////////////////// Method

        #region 검색하기 2 - Search2(title)

        /// <summary>
        /// 검색하기 2
        /// </summary>
        /// <param name="title">제목</param>
        /// <returns>제목 배열</returns>
        [OperationContract]
        string[] Search2(string title);

        #endregion
    }
}