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.NETFrameworkv4.0.30319aspnet_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.NETFramework64v4.0.30319aspnet_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)