管道和过滤器模式属于数据流架构 管道过滤器模式实例

简单举例如下:
会员搜索过滤模块,要先按姓名搜索,再按编号过滤部分会员.
例子比较简单,按姓名搜索,过滤会员在.两功能上是独立的.
没有依赖性,不过实际中常用来功能有依赖性解决并行开发的.
例子中简单只有一个数据源.实际中常常是用来处理两个数据源.
第一个是作为输入的,第二个则是作为输出的.

谁有更好的理解和应用?

using System;

using System.Collections.Generic;

using System.Text;

using System.Data;namespace ModeStudy.Pipes_and_Filters

{

    //可用的流动处理数据接口

    public interface IEnableStreamingProcessData<DataSource>

    {

        //例子简单只有一个数据源.

       //实际中常常会是两个数据源.第一个作为,第二个作为输出.

       //记得Java中的过滤器吗?

       //public void doFilter(ServletRequest req, ServletResponse res, FilterChain fc)

       //void Process(DataSourceInput dataInput,out DataSourceOutput dataOutput)        

        void Process(ref DataSource dataSource);

    }    //链条式处理类

    public class ProcessChain<DataSource> where DataSource : new()

    {

        private LinkedList<IEnableStreamingProcessData<DataSource>> _links = new LinkedList<IEnableStreamingProcessData<DataSource>>();        public void AddLink(LinkedListNode<IEnableStreamingProcessData<DataSource>> link)

        {

            _links.AddLast(link);

        }        public void Process(ref DataSource dataSource)

        {

            foreach (IEnableStreamingProcessData<DataSource> element in _links)

            {

                element.Process(ref dataSource);

            }

        }

    }    //搜索会员类

    public class MembersSearch : IEnableStreamingProcessData<DataTable>

    {

        private string _searchName;        public string SearchName

        {

            get { return _searchName; }

            set { _searchName = value; }

        }        public MembersSearch()

        {

            this.Reset();

        }        public void Reset()

        {

            _searchName = string.Empty;

        }        #region IEnableStreamingProcessData<DataTable> 成员
        public void Process(ref DataTable dataSource)

        {

            dataSource.DefaultView.RowFilter = "name like '%" + this.SearchName+"%'";

            dataSource = dataSource.DefaultView.ToTable();

        }        #endregion

    }    //会员过滤类

    public class MembersFilter : IEnableStreamingProcessData<DataTable>

    {

        private int _id;        public int FilterID

        {

            get { return _id; }

            set { _id = value; }

        }        public MembersFilter()

        {

            this.Reset();

        }        public void Reset()

        {

            _id = -1;

        }        #region IEnableStreamingProcessData<DataTable> 成员
        public void Process(ref DataTable dataSource)

        {

            dataSource.DefaultView.RowFilter = "id <>" + this.FilterID.ToString();

            dataSource = dataSource.DefaultView.ToTable();

        }        #endregion

    }    //会员搜索单例工厂

    public static class MemberSearchFactory

    {

        private static MembersSearch memSearch;

        private static MembersFilter memFilter;        public static IEnableStreamingProcessData<DataTable> MemberSearchInstance(string searchName)

        {

            if (null == memSearch)

                memSearch = new MembersSearch();

            memSearch.Reset();

            memSearch.SearchName = searchName;

            return memSearch;

        }        public static IEnableStreamingProcessData<DataTable> MemberFilterInstance(int filterID)

        {

            if (null == memFilter)

                memFilter = new MembersFilter();

            memFilter.Reset();

            memFilter.FilterID = filterID;

            return memFilter;

        }

    }    public class Test

    {

        public void Process()

        {

            //构造一个具有 id, name列的DataTable.,并添加三条数据.

            DataTable table = new DataTable();

            DataColumnCollection columns = table.Columns;

            columns.Add(new DataColumn("id",typeof(int)));

            columns.Add(new DataColumn("name",typeof(string)));

            DataRow row = table.NewRow();

            row["id"]=1;

            row["name"]="tyweber";

            table.Rows.Add(row);

            row = table.NewRow();

            row["id"] = 2;

            row["name"] = "admin";

            table.Rows.Add(row);

            row = table.NewRow();

            row["id"] = 3;

            row["name"] = "tyweber_zouyong";

            table.Rows.Add(row);            //实例化链条处理类,进行筛选DataTable中的数据.

            ProcessChain<DataTable> chain = new ProcessChain<DataTable>();            IEnableStreamingProcessData<DataTable> memSearch = MemberSearchFactory.MemberSearchInstance("tyweber");

            IEnableStreamingProcessData<DataTable> memFilter = MemberSearchFactory.MemberFilterInstance(1);            LinkedListNode<IEnableStreamingProcessData<DataTable>> nodeSearch = new LinkedListNode<IEnableStreamingProcessData<DataTable>>(

                memSearch

                );

            LinkedListNode<IEnableStreamingProcessData<DataTable>> nodeFilter = new LinkedListNode<IEnableStreamingProcessData<DataTable>>(

                memFilter

                );            chain.AddLink(nodeSearch);

            chain.AddLink(nodeFilter);

            

            chain.Process(ref table);            foreach (DataRow r in table.Rows)

            {

                Console.WriteLine(r["name"]);

            }

        }

    }

}