public static DataTable GetData()
        {
            using (SqlConnection conn = new SqlConnection(strSqlConn))
            {
                using (SqlCommand comd = new SqlCommand("procedure_get_data", conn))
                {
                    comd.CommandType = CommandType.StoredProcedure;
                    SqlDataAdapter sqlDa = new SqlDataAdapter(comd);
                    DataTable dtTable = new DataTable();
                    if (conn.State == ConnectionState.Closed) conn.Open();
                    try
                    {
                        sqlDa.Fill(dtTable);
                    }
                    finally
                    {
                        sqlDa.Dispose();
                    }
                    return dtTable;
                }
            }
        }
　　　……

      DataTable dtData = null;
        if(Cache[strCacheKey] == null)
        {
            dtData = GetData();
            context.Cache.Insert(strCacheKey,dtData,null,DateTime.Now.AddMinutes(20),System.Web.Caching.Cache.NoSlidingExpiration);
        }
        else
        {
            dtData = Cache[strCacheKey] as DataTable;
        }