适配器模式

  class Program
    {
        static void Main(string[] args)
        {
            INewQuery select = AdapterFactory.CreateAdapter();

            object o = select.Query(); 

        }
    }

    /// <summary>
    /// 适配器工厂,这个地方是用来读取配置文件，确定系统是要用XML查询，还是DB查询
    /// </summary>
    public class AdapterFactory
    {
        public static INewQuery CreateAdapter()
        {
            return (INewQuery)Activator.CreateInstance(Type.GetType(""));
        }
    }

    /// <summary>
    /// XML适配器
    /// </summary>
    public class XMLAdapter : INewQuery
    {

        /// <summary>
        /// 这个地方是要把旧的系统，包括到新系统中
        /// </summary>
        private XMLOldQuery query = new XMLOldQuery();
        public object GetList()
        {
            ///旧代码+新代码，在这里面写
            return query.Query();
        }
    }

    /// <summary>
    /// DB适配器
    /// </summary>
    public class DbAdapter : INewQuery
    {
        /// <summary>
        /// 这个地方是要把旧的系统，包括到新系统中
        /// </summary>
        private DbOldQuery query = new DbOldQuery();
        public object GetList()
        {
            ///旧代码+新代码，在这里面写
            return query.Query();
        }
    }


    /// <summary>
    /// 新查询接口
    /// </summary>
    public interface INewQuery
    {
        object Query();
    }

    /// <summary>
    /// 旧的查询接口
    /// </summary>
    public interface IOldQuery
    {
        object Query();
    }
    /// <summary>
    /// 实现XML查询
    /// </summary>
    public class XMLOldQuery : IOldQuery
    {
        public object Query()
        {
            throw new NotImplementedException();
        }
    }
    /// <summary>
    /// 实现DB查询
    /// </summary>
    public class DbOldQuery : IOldQuery
    {
        public object Query()
        {
            throw new NotImplementedException();
        }
    }