数据筛选和API优化,NET中数据缓存和输出缓存详解

筛选数据

须求:若是数据库中留存OrderNum相同,且IsDefault分化的笔录,那么IsDefault值为0的记录将替换值为1的记录(IsDefault值为1的笔录不突显)。

葡京娱乐网 1

出于查出来的数额不多,100条以内,所以小编是一向全体询问到List内存中,然后在内部存款和储蓄器中开始展览多少过滤的操作,思来想去都以为自家如下的兑现情势很low,可是自身时代又没悟出好的措施,不掌握我们有没有好的艺术?

            var newList = list.ToList();
            //筛选出哪些排序号有重复
            var orderNumList = newList.GroupBy(g => g.OrderNum).Select(g => new { orderNum = g.Key, count = g.Count() }).Where(g => g.count > 1).Select(s => s.orderNum).ToList();
            var cfList = newList.Where(w => orderNumList.Contains(w.OrderNum)); //获取有重复排序号的记录

            var cfDefaultList = cfList.Where(w => w.IsDefault);  //默认模块记录
            var cfNoDefaultList = cfList.Where(w => w.IsDefault == false); //非默认模块记录

            var intersectedList = from d in cfDefaultList join f in cfNoDefaultList on d.OrderNum equals f.OrderNum where d.IsDefault!= f.IsDefault select d;

            var newIntersectedList = intersectedList.Distinct().ToArray(); //排序号相同,既存在默认记录也存在非默认记录的数据 

                if (newIntersectedList != null && newIntersectedList.Length > 0)
                {
                    for (int i = 0; i < newIntersectedList.Length; i++)
                    {
                        if (newList.Contains(newIntersectedList[i]))
                        {
                            newList.Remove(newIntersectedList[i]);
                        }
                    }
                }
           newList = newList.OrderBy(x => x.OrderNum).ToList();

 以上的newList就代码截图中的数据。

出口缓存Output caching

优化API接口

有贰个API接口常常卡顿,而且很不安宁,快的时候2~3秒,慢的时候10秒去了。

接口须要:依据社区ID获取促销券记录。

分析:

  • 担负给API接口提供数据的连串中,缺乏许多索引,存在不少慢查询视图。
  • 本来的LINQ完毕格局是在内部存款和储蓄器中分页,响应速度太慢。
  • 并发请求的气象下,能源占用。

优化思路:

  数据缓存Data caching

① 、使用缓存

同叁个社区的人在同一时间所看到的打折券记录应当是同等的,而且大家应该允许脏读,大家在12306下边买火车票的时候,日常也会看到展现有票,可是下单又从未了,大概是运用了缓存,那么我们那里其实同样的能够利用缓存来缓解并发难题。

在WebAPI上边加缓存,那么又分为客户端缓存和服务器缓存。而小编辈通晓,在ASP.NET
WebForm和ASP.NET
MVC中都以有页面输出缓存的,而在WebAPI中暗中同意没有,从NuGet上边下载WebApi.OutputCache.V2,然后再API接口上添加 

[CacheOutput(ClientTimeSpan = 5)]//, ServerTimeSpan = 5

自己那里无法直接利用服务器输出缓存,那是因为不大概捕获缓存变量参数。因为我们API接口的恳求参数是string
appParam,字符串类型的,它是2个json对象进过base6三位编码,然后再进过url编码生成的字符串。

大家只能解析后,获取社区ID,然后依照社区ID来安装缓存,把社区ID+
pageIndex就视作缓存的Key,考虑到要求缓存的数据量一点都不大,这里自身直接使用.NET自带的缓存,引入命名空间:System.Web.Caching;

      private static System.Web.Caching.Cache ObjCache = HttpRuntime.Cache;
        /// <summary>
        /// 设置当前指定Key的Cache值,并限定过期时间 
        /// </summary>
        /// <param name="Key">缓存Key</param>
        /// <param name="Obj">缓存的值</param>
        /// <param name="TimeOuts">超时时间(秒)</param>
        public static void SetCacheSeconds(string Key, object Obj, double TimeOuts)
        {
            ObjCache.Insert(Key, Obj, null, System.DateTime.Now.AddSeconds(TimeOuts), TimeSpan.Zero);
        }
        /// <summary>
        /// 获取当前指定Key的Cache值
        /// </summary>
        /// <param name="Key">缓存Key</param>
        /// <returns>缓存的值</returns>
        public static object GetCache(string Key)
        {
            return ObjCache[Key];
        }

葡京娱乐网,缓存操作类Cache完整代码如下:

葡京娱乐网 2葡京娱乐网 3

/*==================================
 * Author:
 * CreateTime:2014-7-15 17:26:29
 * Description:Cache操作类
 ===================================*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.Caching;
using System.Runtime.CompilerServices;
using System.Web;
using System.Security.Policy;

namespace SSY.Util
{
    /// <summary>
    /// 缓存处理相关类
    /// </summary>
    public class Cache
    {
        private static System.Web.Caching.Cache ObjCache = HttpRuntime.Cache;
        private static short TimeOut = 720;

        #region 清除指定键值的缓存
        /// <summary>
        /// 清除指定键值的缓存
        /// </summary>
        /// <param name="Key">要清除的缓存的key值</param>
        public static void Clear(string Key)
        {
            if (ObjCache[Key] != null)
            {
                ObjCache.Remove(Key);
            }
        }
        #endregion

        #region 返回系统中缓存的个数
        /// <summary>
        /// 返回系统中缓存的个数
        /// </summary>
        /// <returns>缓存个数</returns>
        public static int Count()
        {
            return ObjCache.Count;
        }
        #endregion

        #region 获取当前指定Key的Cache值
        /// <summary>
        /// 获取当前指定Key的Cache值
        /// </summary>
        /// <param name="Key">缓存Key</param>
        /// <returns>缓存的值</returns>
        public static object GetCache(string Key)
        {
            return ObjCache[Key];
        }
        #endregion

        #region 设置当前指定Key的Cache值
        /// <summary>
        /// 设置当前指定Key的Cache值 
        /// </summary>
        /// <param name="Key">缓存Key</param>
        /// <param name="Obj">缓存的值</param>
        public static void SetCache(string Key, object Obj)
        {
            ObjCache.Insert(Key, Obj);
        }
        #endregion

        #region 设置当前指定Key的Cache值,并限定过期时间
        /// <summary>
        /// 设置当前指定Key的Cache值,并限定过期时间 
        /// </summary>
        /// <param name="Key">缓存Key</param>
        /// <param name="Obj">缓存的值</param>
        /// <param name="TimeOuts">超时时间(分钟)</param>
        public static void SetCache(string Key, object Obj, int TimeOuts)
        {
            ObjCache.Insert(Key, Obj, null, System.DateTime.Now.AddMinutes((double)TimeOuts), TimeSpan.Zero);
        }
        /// <summary>
        /// 设置当前指定Key的Cache值,并限定过期时间 
        /// </summary>
        /// <param name="Key">缓存Key</param>
        /// <param name="Obj">缓存的值</param>
        /// <param name="TimeOuts">超时时间(秒)</param>
        public static void SetCacheSeconds(string Key, object Obj, double TimeOuts)
        {
            ObjCache.Insert(Key, Obj, null, System.DateTime.Now.AddSeconds(TimeOuts), TimeSpan.Zero);
        }
        #endregion

        #region 设置当前指定Key的Cache值,依赖文件过期
        /// <summary>
        /// 设置当前指定Key的Cache值,依赖文件过期 
        /// </summary>
        /// <param name="Key">缓存Key</param>
        /// <param name="Obj">缓存的值</param>
        /// <param name="Files">相对地址,例如"~/files.xml"</param>
        public static void SetCache(string Key, object Obj, string Files)
        {
            CacheDependency cacheDep = new CacheDependency(System.Web.HttpContext.Current.Server.MapPath(Files),System.DateTime.Now);
            SetCache(Key, Obj, TimeOut, cacheDep, CacheItemPriority.High);
        }
        #endregion

        #region 设置当前指定Key的Cache值
        /// <summary>
        /// 设置当前指定Key的Cache值
        /// </summary>
        /// <param name="Key">缓存Key</param>
        /// <param name="Obj">缓存的值</param>
        /// <param name="Priority">撤销缓存的优先值,此参数的值取自枚举变量“CacheItemPriority”,优先级低的数据项将先被删除。此参数主要用在缓存退出对象时.</param>
        public static void SetCache(string Key, object Obj, CacheItemPriority Priority)
        {
            SetCache(Key, Obj, TimeOut, null, Priority);
        }
        #endregion

        #region 设置当前指定Key的Cache值
        /// <summary>
        /// 设置当前指定Key的Cache值
        /// </summary>
        /// <param name="Key">缓存Key</param>
        /// <param name="Obj">缓存的值</param>
        /// <param name="TimeOuts">一个TimeSpan,表示缓存参数将在多长时间以后被删除</param>
        /// <param name="CacheDep">缓存的依赖项,需要一个CacheDependency,可初始化一个</param>
        /// <param name="Priority">撤销缓存的优先值,此参数的值取自枚举变量“CacheItemPriority”,优先级低的数据项将先被删除。此参数主要用在缓存退出对象时</param>
        public static void SetCache(string Key, object Obj, int TimeOuts, CacheDependency CacheDep, CacheItemPriority Priority)
        {
            ObjCache.Insert(Key, Obj, CacheDep, System.DateTime.MaxValue, TimeSpan.FromHours((double)TimeOuts), Priority, null);
        }
        #endregion
    }
}

View Code

修改API接口代码:

           #region added by zouqj 2017-3-7
           var result = Util.Cache.GetCache(CommunityID+ pageIndex) as Result<List<GetAvailableCouponsModel>>;
           if (result==null) //不存在则写入缓存
           {
               //组装参数
               Dictionary<string, string> inParams = new Dictionary<string, string>();
               inParams.Add("UserId", userId);
               inParams.Add("PageIndex", pageIndex);
               inParams.Add("PageSize", pageSize);
               inParams.Add("CommunityID", CommunityID+ pageIndex);
               ...

               RequestParam RequestParam = GetRequestParam(methodName, inParams, AuthenticationId);
               var jsonContent = JsonConvert.SerializeObject(RequestParam);
               result = DoPost<List<GetAvailableCouponsModel>>(jsonContent, PostUrl);

               Util.Cache.SetCacheSeconds(CommunityID, result, 10); //写入缓存
           }
           return result;

  1. 出口缓存(Output Caching)

贰 、改为存款和储蓄进度完毕

因为那么些接口的业务逻辑比较复杂,从前的Linq代码写了好长一大串,获取的记录数很多,而且还是在内部存款和储蓄器中开始展览分页落成,所以本人将本来的LINQ达成代码修改为分页存款和储蓄进度实现。

储存进程代码如下:

葡京娱乐网 4葡京娱乐网 5

------------------------------------------创建领券中心存储过程 created by zouqj-2017-3-1-----------------------------------
IF EXISTS(Select Name From Sysobjects Where Name='usp_GetAvailableCoupons' And Xtype='P')
DROP PROCEDURE usp_GetAvailableCoupons
GO
CREATE PROC usp_GetAvailableCouponsl
(
@PageIndex int, --页码
@PageSize int, --每页容纳的记录数
@Sort NVARCHAR(50), --排序字段及规则,不用加order by
@hostName nvarchar(100),--服务器地址
@CommunityID UNIQUEIDENTIFIER, --社区
@IsGetCount BIT --是否得到记录总数,1为得到记录总数,0为不得到记录总数,返回记录集
)
AS
-------------------------------定义变量-----------------------
declare @strSql NVARCHAR(max);
DECLARE  @dt datetime2(7) --查询时间
SET @dt=GETDATE();
set nocount on;
----------------------------------------SQL开始--------------------------------------------无分类
IF @IsGetCount=1
BEGIN

SET @strSql=N'SELECT COUNT(*) FROM (SELECT DISTINCT t.CampaignID from
(SELECT 
c.ID AS CampaignID
 FROM MK_Campaign c WITH ( NOLOCK ) INNER JOIN MK_CouponConfig f WITH ( NOLOCK ) ON c.ID=f.CampaignID
           INNER JOIN MK_Coupon p WITH ( NOLOCK ) ON f.CouponID=p.ID
           WHERE f.CouponGetType=2 AND f.ReceiveStartTime <=@dt AND f.ReceiveEndTime>= @dt
           AND c.State=4 --执行中
           AND p.WholeNetwork=1 --全网优惠
UNION ALL
SELECT
    a.[ID] AS CampaignID
    FROM  [dbo].[MK_Campaign] AS a WITH ( NOLOCK )
        INNER JOIN [dbo].[MK_CouponConfig] AS b  WITH ( NOLOCK ) ON a.[ID] = b.[CampaignID]
        AND (b.[ReceiveStartTime] <= @dt) AND (b.[ReceiveEndTime] >= @dt) AND (2 = b.[CouponGetType]) AND (4 = a.[State]) 
        INNER JOIN [dbo].[MK_Coupon] AS c WITH ( NOLOCK ) ON b.[CouponID] = c.[ID]
        INNER JOIN [dbo].[MK_CouponRestriction] AS d  WITH ( NOLOCK ) ON c.[ID] = d.[CompainID]
        LEFT OUTER JOIN [dbo].[MK_CouponRestrictCategory] AS e WITH ( NOLOCK ) ON d.[ID] = e.[CouponRestrictionID]
        LEFT OUTER JOIN [dbo].[MK_CouponRestrictionOrg] AS f WITH ( NOLOCK ) ON d.[ID] = f.[CouponRestrictionID]
        INNER JOIN [dbo].[ViewOrganizationCommunityForInterface] AS v ON f.[OrgID] = v.[ID]    
    where v.CommunityID=@CommunityID  and 1 = d.[Type]
UNION ALL
SELECT 
   a.ID AS CampaignID
   FROM MK_Campaign a  WITH ( NOLOCK ) 
             INNER JOIN MK_CouponConfig b WITH ( NOLOCK ) ON a.ID=b.CampaignID AND (b.[ReceiveStartTime] <= @dt) AND (b.[ReceiveEndTime] >=@dt) 
             INNER JOIN [dbo].[MK_Coupon] AS c WITH ( NOLOCK ) ON b.[CouponID] = c.[ID] and (2 = b.[CouponGetType]) AND (4 = a.[State]) 
             INNER JOIN [dbo].[MK_CouponRestriction] AS d WITH ( NOLOCK ) ON c.[ID] = d.[CompainID]  AND (2 = d.[Type]) 
             LEFT OUTER JOIN MK_CouponRestrictionProduct AS e WITH ( NOLOCK ) ON d.[ID] = e.[CouponRestrictionID] 
             LEFT OUTER JOIN SL_Product AS f WITH ( NOLOCK ) ON (e.ProductID = f.ID)
             INNER JOIN ViewOrganizationCommunityForInterface v ON v.ID=f.PublisherID
   where v.CommunityID=@CommunityID
   ) t
 ) AS tt'
----------------------------------------------------------------------------------
END
ELSE
BEGIN
SET @strSql=N'SELECT DISTINCT t.* from(
SELECT 
          c.ID AS CampaignID,
          c.Name AS CampaignName,
          f.ValidityStartTime AS CampaignStartTime,
          f.ValidityEndTime AS CampaignEndTime,
          p.Name AS CouponsName,
          p.Price AS CouponsAmount,
          (CASE WHEN p.IsLimited =1 THEN 1 ELSE 2 END) AS IsLimited,
          p.FullAmount AS MinAmount,
          f.ValidityEndTime AS CouponsEndTime,
          f.ValidityStartTime AS CouponsStartTime,
          (CASE WHEN f.IsRepeateGet =1 THEN 1 ELSE 2 END) AS IsCanRepeatedReceive,
          f.ReceiveAddress AS ReceiveAddress,
          f.ReceiveEndTime AS ReceiveEndTime,
          f.ReceiveStartTime AS ReceiveStartTime,
          f.ReceiveMode AS ReceiveMethod,
          f.ProvideNum AS ReceiveNum,
          p.CreateTime AS CreateTime,
          p.Price AS Price,
          f.RemainCouponNum AS RemainCouponNum,
          f.ID AS CouponConfigId,
          p.WholeNetwork AS CouponsType,
          (CASE WHEN f.IconUrl IS NULL THEN N'''' WHEN f.IconUrl=N'''' THEN N'''' ELSE @hostName+f.IconUrl END) AS IconUrl 
FROM MK_Campaign c WITH ( NOLOCK ) 
                 INNER JOIN MK_CouponConfig f WITH ( NOLOCK ) ON c.ID=f.CampaignID
                 INNER JOIN MK_Coupon p WITH ( NOLOCK ) ON f.CouponID=p.ID
          WHERE f.CouponGetType=2 AND f.ReceiveStartTime <= @dt AND f.ReceiveEndTime>= @dt AND c.State=4 AND p.WholeNetwork=1 --全网优惠
--
UNION ALL
          SELECT a.[ID] AS CampaignID,
          a.[Name] AS CampaignName, 
          b.[ValidityStartTime] AS CampaignStartTime,
          b.[ValidityEndTime] AS CampaignEndTime, 
          c.[Name] AS CouponsName, 
          c.[Price] AS CouponsAmount, 
          CASE WHEN (c.[IsLimited] = 1) THEN 1 ELSE 2 END AS IsLimited, 
          c.[FullAmount] AS MinAmount, 
          b.[ValidityEndTime] AS CouponsEndTime, 
          b.[ValidityStartTime] AS CouponsStartTime, 
          CASE WHEN (b.[IsRepeateGet] = 1) THEN 1 ELSE 2 END AS IsCanRepeatedReceive, 
          b.[ReceiveAddress] AS [ReceiveAddress], 
          b.[ReceiveEndTime] AS [ReceiveEndTime], 
          b.[ReceiveStartTime] AS [ReceiveStartTime], 
          b.[ReceiveMode] AS ReceiveMethod, 
          b.[ProvideNum] AS ReceiveNum, 
          c.[CreateTime] AS CreateTime, 
          c.[Price] AS Price, 
          b.[RemainCouponNum] AS RemainCouponNum, 
          b.[ID] AS CouponConfigId, 
          e.[Type] AS CouponsType, 
          CASE WHEN (b.[IconUrl] = N'''' OR b.[IconUrl] IS NULL) THEN N'''' ELSE @hostName+b.[IconUrl] END AS IconUrl
                    FROM  [dbo].[MK_Campaign] AS a WITH ( NOLOCK )
                        INNER JOIN [dbo].[MK_CouponConfig] AS b  WITH ( NOLOCK ) ON a.[ID] = b.[CampaignID] AND (b.[ReceiveStartTime] <= @dt) AND (b.[ReceiveEndTime] >= @dt) AND (2 = b.[CouponGetType]) AND (4 = a.[State]) 
                        INNER JOIN [dbo].[MK_Coupon] AS c WITH ( NOLOCK ) ON b.[CouponID] = c.[ID]
                        INNER JOIN [dbo].[MK_CouponRestriction] AS d  WITH ( NOLOCK ) ON c.[ID] = d.[CompainID]
                        LEFT OUTER JOIN [dbo].[MK_CouponRestrictCategory] AS e WITH ( NOLOCK ) ON d.[ID] = e.[CouponRestrictionID]
                        LEFT OUTER JOIN [dbo].[MK_CouponRestrictionOrg] AS f WITH ( NOLOCK ) ON d.[ID] = f.[CouponRestrictionID]
                        INNER JOIN [dbo].[ViewOrganizationCommunityForInterface] AS v ON f.[OrgID] = v.[ID]    
                    where v.CommunityID=@CommunityID  and 1 = d.[Type]
UNION ALL
SELECT 
       a.ID AS CampaignID,
       a.Name AS CampaignName,
       b.ValidityStartTime AS CampaignStartTime,
       b.ValidityEndTime AS CampaignEndTime,
       c.Name AS CouponsName,
       c.Price AS CouponsAmount,
       (CASE WHEN c.IsLimited=1 then 1 else 2 END) AS IsLimited,
       c.FullAmount AS MinAmount,
       b.ValidityEndTime AS CouponsEndTime,
       b.ValidityStartTime AS CouponsStartTime,
       (case when b.IsRepeateGet=1 then 1 else 2 END) AS IsCanRepeatedReceive,
       b.ReceiveAddress AS ReceiveAddress,
       b.ReceiveEndTime AS ReceiveEndTime,
       b.ReceiveStartTime AS ReceiveStartTime,
       b.ReceiveMode AS ReceiveMethod,
       b.ProvideNum AS ReceiveNum,
       c.CreateTime AS CreateTime,
       c.Price AS Price,
       b.RemainCouponNum AS RemainCouponNum,
       b.ID AS CouponConfigId,
       d.[TYPE] AS CouponsType,
       (CASE WHEN b.IconUrl IS NULL THEN N'''' WHEN b.IconUrl=N'''' THEN N'''' ELSE @hostName+b.IconUrl END) AS IconUrl
   FROM MK_Campaign a  WITH ( NOLOCK ) 
                    INNER JOIN MK_CouponConfig b WITH ( NOLOCK ) ON a.ID=b.CampaignID AND (b.[ReceiveStartTime] <= @dt) AND (b.[ReceiveEndTime] >= @dt) 
                    INNER JOIN [dbo].[MK_Coupon] AS c WITH ( NOLOCK ) ON b.[CouponID] = c.[ID] and (2 = b.[CouponGetType]) AND (4 = a.[State]) 
                    INNER JOIN [dbo].[MK_CouponRestriction] AS d WITH ( NOLOCK ) ON c.[ID] = d.[CompainID]  AND (2 = d.[Type]) 
                    LEFT OUTER JOIN MK_CouponRestrictionProduct AS e WITH ( NOLOCK ) ON d.[ID] = e.[CouponRestrictionID] 
                    LEFT OUTER JOIN SL_Product AS f WITH ( NOLOCK ) ON (e.ProductID = f.ID)
                    INNER JOIN ViewOrganizationCommunityForInterface v ON v.ID=f.PublisherID
                    where v.CommunityID=@CommunityID
   ) t
ORDER BY t.Price--@Sort
offset (@PageIndex-1)*@PageSize ROWS  FETCH NEXT @PageIndex*@PageSize ROWS ONLY'
end
--执行SQL
exec sp_executesql @strSql,N'@PageIndex int,@PageSize int,@Sort nvarchar(50),@hostName nvarchar(100),@CommunityID UNIQUEIDENTIFIER,@IsGetCount bit,@dt datetime2(7)',@PageIndex =@PageIndex,@PageSize =@PageSize,@Sort=@Sort,@hostName=@hostName,@CommunityID=@CommunityID,@IsGetCount=@IsGetCount,@dt=@dt
set nocount off;

View Code

此间要求注意的是,存款和储蓄执行是,先关闭计数,set nocount on;,然后再打开set
nocount off;,那样能够升官品质。还有就是利用WITH ( NOLOCK
)允许脏读,进步查询成效。

那边碰着2个很奇特的标题,作者使用exec
sp_executesql
@strSql,N’….’的不二法门来推行是没很是的,而一旦本人利用拼接sql的方法,会报错,因为sql字符串被截断了,只截取到了四千个字符长度,就算作者把字符串变量长度设置为nvarchar(max)也没用。

分页格局选取Sqlserver2012以上版本才支撑的快速方式:offset … FETCH NEXT
…ROWS ONLY

原本Linq的进行时间测试:

葡京娱乐网 6BLW.png)葡京娱乐网 7

本人修改为存款和储蓄进度之后的执行时间测试:

葡京娱乐网 8

特性差异拾叁分鲜明。

  使用输出缓存,你能够缓存最后输出的HTML页面,当相同的页面重新恳请的时候,ASP.NET不会再履行页面包车型客车生命周期和连锁代码而是径直行使缓存的页面,语法如下:

  <%@
OutputCache Duration=”60” VaryByParam=”None”  %>

  Duration
属性设置页面将被缓存60妙。任何的用户请求都会被缓存,在缓冲的60秒内一律的请求都会一向动用缓存的页面。当缓存过期后ASP.NET会再次实施页面代码并且为下三个60秒创制一个新的HTML缓存。

<%@ Page Language=”C#” MastERPageFile=”~/MasterPage.master” AutoEventWireup=”true” CodeFile=”OutputCachingTest.aspx.cs” Inherits=”OutputCachingTest” Title=”Page” %> 
<%@ OutputCache Duration=”20″ VaryByParam=”None” %> 
<asp:Content ID=”Content1″ ContentPlaceHolderID=”ContentPlaceHolder1″ runat=”Server”>  
   <div class=”title”>Output
Cache</div> 
   Date: <asp:Label ID=”lblDate” runat=”server” Text=”” /> 
   Time: <asp:Label ID=”lblTime” runat=”server” Text=”” />        
</asp:Content>

 

protected void Page_Load(object sender, EventArgs e) 

  lblDate.Text = DateTime.Now.ToShortDateString(); 
  lblTime.Text = DateTime.Now.ToLongTimeString(); 
}

   在那个例子中页面将被缓存20秒。

  经过询问字符串缓存(Cache by Query String )

  在事实上行使中页面往往会依据部分参数动态的变动页面的剧情。就算您的页面是因此查询字符串来获取新闻的,你能够遵照查询字符串很简单的缓存页面包车型地铁两样拷贝。VarByParam=”None”钦命ASP.NET只存储缓存页面包车型地铁1个正片。VarByParam=”*”
钦定ASP.NET依据差别的询问字符串存款和储蓄差别的缓存页面。

<%@ OutputCache
Duration=”60″ VaryByParam=”*” %> 
<div align=”right”> 
   <a href=”OutputCachingTest2.aspx”>No
Query String</a> |  
   <a href=”OutputCachingTest2.aspx?id=1″>ID
1</a> |  
   <a href=”OutputCachingTest2.aspx?id=2″>ID
2</a> |  
   <a href=”OutputCachingTest2.aspx?id=3″>ID
3</a> | 
   <a href=”OutputCachingTest2.aspx?id=3&langid=1″>ID
3</a> 
</div>

 

  上边的例子中,在询问字符串中传了分裂的ID.ASP.NET为每3个ID都存款和储蓄了单独的缓存页面。那种艺术会有一对题目正是当查问字符串范围很广的时候。

  这几个时候我们能够在VarByParam
属性中钦赐主要的询问字符串变量的名字,如下:

  %@OutputCacheDuration=”60″VaryByParam=”id;langid”%

 

  那样,ASP.NET能够依据id” or “langid”来缓存不一致的缓存版本。

  自定义缓存(Custom Caching)

  你也得以创建自定义的次第来缓存页面。ASP.net提供了一种很便利的章程来创制自定义缓存,使用VarByCustom属性内定自定义缓存类型的名字。

  你还要创设为缓存生成自定义字符串的方法,如下:

  public override stringGetVaryByCustomString(HttpContext
context, stringcustom) 
  { 
  if(custom == “browser”) 
  { 
  returncontext.Request.Browser.Browser + 
  context.Request.Browser.MajorVersion; 
  } 
  else 
  { 
  return base.GetVaryByCustomString(context, custom); 
  } 
  }

 

  那一个点子必须写在global.asax文件中。ASP.NET使用该方法重临的字符串来兑现缓存,如若那个措施在不一致的乞请中回到相同的字符串,ASP.NET就会动用缓存的页面,不然就会扭转新的缓存版本。

  下边包车型客车例子中GetVaryByCustomString()方法遵照浏览器的名字创办缓存字符串,ASP.NET会遵照不相同的浏览器请求创立不相同版本的缓存。

  控件缓存(Control Cache )

  下面的缓存技术能够让你很简单的缓存整个页面,假若要缓存钦定控件的始末,能够经过点名VaryByControl
属性来完毕。

  %@OutputCacheDuration=”20″VaryByControl=”MyControl_1″%

 

  上面代码ASP.NET将会缓存MyControl_1控件二十分钟。假设要基于一些属性值来缓存控件只需求将OutPutCache指令出席*.ascx页面。

<%@Control Language=”C#”AutoEventWireup=”true”CodeFile=”MyControl.ascx.cs” 
Inherits=”Controls_MyControl”%> 
<%@OutputCacheDuration=”20″VaryByControl=”EmployeeID”%>  

  VaryByControl=”EmployeeID”告诉ASP.NET依据控件中宣示的EmployeeID属性来创制分歧版本的缓存。

  在 .ascx.cs 文件参预EmplyeeID属性为ASP.NET 缓存使用。

  在页面中扩大控件并且安装 EmployeeID.

    private int_employeeID; 
  public intEmployeeID 
  { 
  get{ return_employeeID; } 
  set{ _employeeID = value;

  } 
  protected voidPage_Load(objectsender, EventArgs e) 
  { 
  lblDate.Text = DateTime.Now.ToShortDateString(); 
  lblTime.Text = DateTime.Now.ToLongTimeString(); 
  lblEmployeeID.Text = EmployeeID.ToString(); 
  }

 

     缓存配置文件(Cache Profile )

  Web.config能够配备缓存相关的设置,

  <system.web> 
  <caching> 
    <outputCacheSettings> 
      <outputCacheProfiles> 
        <addname=”ProductItemCacheProfile” duration=”60″/> 
      </outputCacheProfiles> 
    </outputCacheSettings> 
  </caching> 
</system.web>

 

   你能够经过设置 CacheProfile=”ProfileName” 属性 来行使方面包车型大巴布置:

  %@OutputCacheCacheProfile=”ProductItemCacheProfile”VaryByParam=”None”%

 

  2. 数码缓存(Data Caching)

  ASP.net还提供了另一种灵活的缓存类型:数据缓存。你能够将有个别消耗时间的条条框框插手到2个对象缓存集合中,以键值的方法存款和储蓄。

  Cache[“Name”] = data;

  大家得以经过利用Cache.Insert()方法来安装缓存的晚点,优先级,依赖项等。

  date1 = DateTime.Now;Cache.Insert(“Date1”, date1, null,
DateTime.Now.AddSeconds(20), TimeSpan.Zero);

  ASP.NET允许你设置3个绝对过期时间或滑动过期时光,但不能同时采用。

  缓存重视项Cache dependency

  缓存注重项使缓存依赖于任何能源,当正视项改成时,缓存条目项将机关从缓存中移除。缓存依赖项能够是应用程序的
Cache 中的文件、目录或与此外对象的键。要是文件或目录更改,缓存就会晚点。

    date2 = DateTime.Now; 
  string[] cacheKeys = { “Date1”}; 
  CacheDependency cacheDepn = newCacheDependency(null,
cacheKeys); 
  Cache.Insert(“Date2”, date2,
cacheDepn);

 

  上边的例证“Date2”缓存对象依赖“Date1”缓存条目,当 “Date1”
对象过期后“Date2” 将会活动过期。CacheDependency(null,
cacheKeys)中的第二个参数为空是出于大家只监视缓存键的变更情况。

  回调函数和缓存优先级(Callback Method and Cache Priority)

  ASP.NET允许大家写贰个回调函数,当缓存条目从缓存中移除的时候接触。还足以设置缓存条指标先期级。

  protected void Page_Load(object sender, EventArgs e) 
  { 
  DateTime? date1 = (DateTime?)Cache[“Date1”]; 
  if (!date1.HasValue) // date1 ==
null 
  { 
  date1 = DateTime.Now; 
  Cache.Insert(“Date1”,
date1, null, DateTime.Now.AddSeconds(20),
TimeSpan.Zero, 
  CacheItemPriority.Default, new CacheItemRemovedCallback(CachedItemRemoveCallBack)); 
  } 
  DateTime? date2 = (DateTime?)Cache[“Date2”]; 
  if (!date2.HasValue) // date2 ==
null 
  { 
  date2 = DateTime.Now; 
  Cache.Insert(“Date2”,
date2, null, DateTime.Now.AddSeconds(40),
TimeSpan.Zero, 
  CacheItemPriority.Default, new CacheItemRemovedCallback(CachedItemRemoveCallBack)); 
  } 
  // Set values in labels 
  lblDate.Text = date1.Value.ToShortDateString(); 
  lblTime.Text = date1.Value.ToLongTimeString(); 
  lblDate1.Text = date2.Value.ToShortDateString(); 
  lblTime1.Text = date2.Value.ToLongTimeString(); 
  } 
  private void CachedItemRemoveCallBack(string key, object value, CacheItemRemovedReason reason) 
  { 
  if (key == “Date1” || key == “Date2”) 
  { 
  Cache.Remove(“Date1”); 
  Cache.Remove(“Date2”); 
  } 
  }

 

  例子中创制了“Date1” 和 “Date2”缓存。“Date1”
在20秒后过期“Date2”为40秒。但是出于大家报了名了移除的回调函数,当“Date1”
或 “Date2”在那之中1个超时都会实施CachedItemRemoveCallBack
方法,在这一个主意中移除了七个缓存条目,ASP.NET还提供了处理缓存条目更新时的回调函数CacheItemUpdateCallback