簡單資料緩衝類（c#）

using System;

using System.Data;

using System.Data.SqlClient;

using System.Threading;

 

namespace WJ.Lib.Base

{

     /// <summary>

     /// DateBuffer 的摘要說明。

     /// </summary>

     public class DateBuffer

     {

        int mGetDateType;   //資料類型

        //object mobjBuffer;  

        string mSql;

        SqlCommand mSqlCom;

        DateTime mFlagDT; //上次更新時間

        int mBufferTime;     //更新時間間隔

        Thread m_Thread;  //逾時時開啟進程更新資料

 

        DataTable mdtBuffer;

 

        public DateBuffer()

        {

            mBufferTime = 2;

        }

 

        public DateBuffer(SqlCommand sSqlCom)

        {

            mBufferTime = 2;

            mSqlCom = sSqlCom;

            //從預存程序中擷取資料

            mGetDateType = 2;

        }

 

 

        public DateBuffer(string sSql)

        {

            mBufferTime = 2;

            Sql = sSql;

            //從查詢語句中擷取資料

            mGetDateType = 1;

        }

 

        /// <summary>

        /// 設定緩衝時間（分鐘）

        /// </summary>

        public int BufferTime

        {

            set

            {

                mBufferTime = value;

            }

        }

 

 

        /// <summary>

        /// 擷取快取資料

        /// </summary>

        public DataTable Buffer

        {

            get

            {

                CheckDate(true);

                return mdtBuffer;

            }

        }

 

        /// <summary>

        /// 設定資料查詢預存程序

        /// </summary>

        public SqlCommand SqlCom

        {

            set

            {

                if (mdtBuffer == null)

                {

                    mdtBuffer = new DataTable();

                }

                mSqlCom = value;

                //從預存程序中擷取資料

                mGetDateType = 2;

                CheckDate(false);

            }

            get

            {

                return mSqlCom;

            }

        }

 

        /// <summary>

        /// 設定資料查詢SQL

        /// </summary>

        public string Sql

        {

            set

            {

                if (mdtBuffer == null)

                {

                    mdtBuffer = new DataTable();

                }

                mSql = value;

                //從查詢語句中擷取資料

                mGetDateType = 1;

                CheckDate(false);

            }

            get

            {

                return mSql;

            }

        }

 

        /// <summary>

        /// 保持資料更新

        /// </summary>

        void CheckDate(bool CheckTime)

        {

            try

            {

                if (!CheckTime)

                {

                    //需要立即更新資料

                    UpdateDate();

                }

                else if (mFlagDT < DateTime.Now)

                {

                    //更新資料時間逾時，採用線程更新資料

                    if(m_Thread == null

                        || (m_Thread.ThreadState != System.Threading.ThreadState.Running

                        && m_Thread.ThreadState != System.Threading.ThreadState.WaitSleepJoin ))

                    {

                        m_Thread = new Thread(new ThreadStart(UpdateDate));

                        m_Thread.Start();

                    }

                }

            }

            catch

            {

            }

        }

 

        void UpdateDate()

        {

            DataTable dt = null;

            try

            {

                if (mGetDateType == 1)

                {

                   //通過查詢語句擷取表資料

                    dt = GetDateTable(mSql);

                }

                else if(mGetDateType == 2)

                {

                   //通過預存程序擷取表資料

                    dt =GetDateTable(ref mSqlCom);

                }

                mFlagDT = DateTime.Now.AddMinutes(mBufferTime);

            }

            catch

            {

            }

            finally

            {

                if (dt != null)

                {

                    mdtBuffer = dt;

                }

            }

        }

 

 

     }

}