NET中数量缓存和输出缓存详解,数据筛选和API优化

筛选数据

急需:要是数据库中留存OrderNum相同,且IsDefault不相同的记录,那么IsDefault值为0的笔录将替换值为1的笔录(IsDefault值为1的记录不彰显)。

图片 1

是因为查出来的多寡不多,100条以内,所以自身是直接全部查询到List内部存储器中,然后在内部存款和储蓄器中开始展览多少过滤的操作,思来想去都觉得自己如下的贯彻方式很low,然则自身时期又没悟出好的办法,不掌握我们有没有好的点子?

            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。

输出缓存Output caching

优化API接口

有三个API接口平时卡顿,而且很不稳定,快的时候2~3秒,慢的时候10秒去了。

接口需要:根据社区ID获取减价券记录。

分析:

  • 承担给API接口提供数据的种类中,贫乏许多索引,存在诸多慢查询视图。
  • 本来的LINQ达成方式是在内部存款和储蓄器中分页,响应速度太慢。
  • 并发请求的境况下,能源占用。

优化思路:

  数据缓存Data caching

壹 、使用缓存

同二个社区的人在同一时半刻间所见到的减价券记录应当是同样的,而且我们应该允许脏读,大家在12306方面买轻轨票的时候,平时也汇合到呈现有票,但是下单又从不了,可能是行使了缓存,那么大家那边实在同样的可以利用缓存来化解并发难点。

在WebAPI下边加缓存,那么又分为客户端缓存和服务器缓存。而大家驾驭,在ASP.NET
WebForm和ASP.NET
MVC中都是有页面输出缓存的,而在WebAPI中默许没有,从NuGet上面下载WebApi.OutputCache.V2,然后再API接口上添加 

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

自己那边无法直接接纳服务器输出缓存,那是因为无法捕获缓存变量参数。因为我们API接口的请求参数是string
appParam,字符串类型的,它是八个json对象进过base陆12人编码,然后再进过url编码生成的字符串。

大家只好解析后,获取社区ID,然后依照社区ID来设置缓存,把社区ID+
pageIndex就作为缓存的Key,考虑到供给缓存的数据量不大,那里笔者平素使用.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];
        }

缓存操作类Cache完整代码如下:

图片 2图片 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. 输出缓存(Output Caching)

二 、改为存款和储蓄进程落成

因为这些接口的业务逻辑比较复杂,在此以前的Linq代码写了好长一大串,获取的记录数很多,而且照旧在内部存款和储蓄器中开始展览分页实现,所以作者将原先的LINQ达成代码修改为分页存款和储蓄进度落成。

仓库储存进度代码如下:

图片 4图片 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

此地需求小心的是,存款和储蓄执行是,先关闭计数,set nocount on;,然后再打开set
nocount off;,那样能够升级品质。还有就是应用WITH ( NOLOCK
)允许脏读,升高查询效能。

此间遭遇贰个很蹊跷的标题,笔者使用exec
sp_executesql
@strSql,N’….’的法子来实施是向来不难题的,而一旦作者利用拼接sql的办法,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。

分页格局使用Sqlserver二〇一一以上版本才支撑的神速情势:offset … FETCH NEXT
…ROWS ONLY

原先Linq的实践时间测试:

图片 6BLW.png)图片 7

自家修改为存款和储蓄进度之后的履行时间测试:

图片 8

品质差别13分引人注目。

  使用输出缓存,你能够缓存最终输出的HTML页面,当相同的页面重新呼吁的时候,ASP.NET不会再实践页面包车型大巴生命周期和血脉相通代码而是直接运用缓存的页面,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秒内一样的央浼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秒成立三个新的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(); 
}

   在这么些事例中页面将被缓存20秒。

  透过查询字符串缓存(Cache by Query String )

  在骨子里行使中页面往往会基于一些参数动态的改变页面包车型客车内容。假设你的页面是经过询问字符串来获取音讯的,你能够依据查询字符串很不难的缓存页面包车型地铁例外拷贝。VarByParam=”None”钦赐ASP.NET只存款和储蓄缓存页面包车型大巴1个拷贝。VarByParam=”*”
内定ASP.NET依据分裂的查询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>

 

  上边包车型地铁事例中,在查询字符串中传了分化的ID.ASP.NET为每1个ID都存款和储蓄了单独的缓存页面。那种方法会有部分难题就是当查问字符串范围很广的时候。

  这么些时候大家能够在VarByParam
属性中内定首要的询问字符串变量的名字,如下:

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

 

  那样,ASP.NET可以依照id” or “langid”来缓存区别的缓存版本。

  自定义缓存(Custom Caching)

  你也足以创建自定义的主次来缓存页面。ASP.net提供了一种很方便的措施来成立自定义缓存,使用VarByCustom属性钦命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法子,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); 
  } 
  }

 

  那几个方式必须写在global.asax文件中。ASP.NET使用该方法再次回到的字符串来兑现缓存,假若那一个法子在不一致的央浼中回到相同的字符串,ASP.NET就会动用缓存的页面,不然就会变动新的缓存版本。

  上边的例证中GetVaryByCustomString()方法遵照浏览器的名字创办缓存字符串,ASP.NET会根据分歧的浏览器请求创造分歧版本的缓存。

  控件缓存(Control Cache )

  上面包车型大巴缓存技术能够让您很不难的缓存整个页面,如果要缓存钦定控件的始末,能够经过点名VaryByControl
属性来达成。

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

 

  上边代码ASP.NET将会缓存MyControl_1控件20秒钟。若是要基于部分属性值来缓存控件只要求将OutPutCache指令参加*.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依照控件中扬言的EmployeeID属性来成立分裂版本的缓存。

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

  在页面中扩展控件并且安装 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能够安插缓存相关的安装,

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

 

   你能够通过安装 CacheProfile=”ProfileName” 属性 来利用方面包车型大巴配置:

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

 

  2. 数据缓存(Data Caching)

  ASP.net还提供了另一种灵活的缓存类型:数据缓存。你能够将部分消耗费时间间的条款参加到2个目的缓存集合中,以键值的法子存款和储蓄。

  Cache[“Name”] = data;

  大家得以经过行使Cache.Insert()方法来设置缓存的晚点,优先级,注重项等。

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

  ASP.NET允许你设置三个相对过期时间或滑动过期日子,但不可能而且选择。

  缓存正视项Cache dependency

  缓存依赖项使缓存重视于其余能源,当正视项改成时,缓存条目项将机关从缓存中移除。缓存信赖项能够是应用程序的
Cache 中的文件、目录或与其余对象的键。假若文件或目录更改,缓存就会晚点。

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

 

  下边包车型大巴例证“Date2”缓存对象正视“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3个参数为空是由于大家只监视缓存键的改动情状。

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

  ASP.NET允许我们写1个回调函数,当缓存条目从缓存中移除的时候接触。还是能安装缓存条目标预先级。

  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”); 
  } 
  }

 

  例子中开创了“Date1” 和 “Date2”缓存。“Date1”
在20秒后过期“Date2”为40秒。不过由于大家报了名了移除的回调函数,当“Date1”
或 “Date2”其中3个超时都会执行CachedItemRemoveCallBack
方法,在那么些艺术中移除了多个缓存条目,ASP.NET还提供了拍卖缓存条目更新时的回调函数CacheItemUpdateCallback