MVC缓存（二）

依赖缓存：

1.监视特定的数据库表，当数据库表里数据发生变化时，自动删除缓存项，并向Cache中添加新的项。

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using System.Web.Mvc;

 namespace MvcCache.Control.Controllers
 {
     public class SqlDependencyController : Controller
     {
         [OutputCache(CacheProfile = "SqlDependencyCache")]
         public ActionResult Index()
         {
             ViewBag.CurrentTime = System.DateTime.Now;
             return View();
         }

     }
 }

2.CacheProfile指向配置文件中name为SqlDependencyCache的缓存配置，然后配置文件中的配置缓存对数据库的依赖。

 <?xml version="1.0" encoding="utf-8"?>
 <!--
   For more information on how to configure your ASP.NET application, please visit
   http://go.microsoft.com/fwlink/?LinkId=169433
   -->

 <configuration>
   <!--数据库连接字符串-->
   <connectionStrings>
     <add name="Conn" connectionString="server=localhost;database=wcfDemo;uid=sa;pwd=123456;" providerName="System.Data.SqlClient"/>
   </connectionStrings>
   <!--数据库连接字符串-->
   <appSettings>
     <add key="webpages:Version" value="2.0.0.0" />
     <add key="webpages:Enabled" value="false" />
     <add key="PreserveLoginUrl" value="true" />
     <add key="ClientValidationEnabled" value="true" />
     <add key="UnobtrusiveJavaScriptEnabled" value="true" />
   </appSettings>
   <system.web>
     <!--配置缓存-->
     <caching>
       <sqlCacheDependency><!--缓存的数据库依赖节-->
         <databases>
           <add name="UserCacheDependency" connectionStringName="Conn" pollTime="500"/><!--Conn：数据库连接字符串的名称，name随便启名，缓存节会用到-->
         </databases>
       </sqlCacheDependency>
       <outputCacheSettings>
         <outputCacheProfiles>
           <add name="SqlDependencyCache" duration="3600" sqlDependency="UserCacheDependency:user"/><!--UserCacheDependency：数据库依赖配置节的名称，user：数据库中需要监听的表名称-->
         </outputCacheProfiles>
       </outputCacheSettings>
     </caching>
     <!--配置缓存-->
     <httpRuntime targetFramework="4.5" />
     <compilation debug="true" targetFramework="4.5" />
     <pages>
       <namespaces>
         <add namespace="System.Web.Helpers" />
         <add namespace="System.Web.Mvc" />
         <add namespace="System.Web.Mvc.Ajax" />
         <add namespace="System.Web.Mvc.Html" />
         <add namespace="System.Web.Routing" />
         <add namespace="System.Web.WebPages" />
       </namespaces>
     </pages>
   </system.web>
   <system.webServer>
     <validation validateIntegratedModeConfiguration="false" />

     <handlers>
       <remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" />
       <remove name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" />
       <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
       <add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
       <add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
       <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
     </handlers>
   </system.webServer>

 </configuration>

3.启用该数据库表的缓存依赖通知功能

打开vs命令工具行，输入：aspnet_regsql -S localhost -U sa -P 123456 -ed -d wcfDemo -et -t user

-S localhost：数据库地址

-U sa：数据库登录名

-P 123456：数据库登录密码

-d wcfDemo：数据库的名称

-t user：表名称(小写)