什么是Cache？
缓存在web应用中是一种以空间换去时间的技术，把频繁访问并且不经常变化的数据存储到内存中，以达到快速访问的目的。在web应用中是比较常见的优化方式。
OutputCacheAttribute
表示一个特性，该特性用于标记将缓存其输出的操作方法。
OutpuCacheAttribute定义
代码片段
[AttributeUsageAttribute(AttributeTargets.Class|AttributeTargets.Method, Inherited = true,
AllowMultiple = false)]
public class OutputCacheAttribute : ActionFilterAttribute,
IExceptionFilter
从上面的代码中可以看到该特性可以应用在类，方法上面。在mvc中，就可以直接在控制器上面或者控制器中的Action上面直接使用，做到细粒度的对缓存的控制。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
namespace Wolfy.OutputCacheDemo.Controllers
{
[OutputCache(Duration = 10)]
public class HomeController : Controller
{
// GET: Home
public string Index()
{
return DateTime.Now.ToString();
}
}
}
上面的代码是将OutputCache特性标记在了控制器类上，以达到该控制器上所有的Action都将应用该特性，过期时间设置为10s。10s后缓存过期，再访问就会更新时间。
OutputCache特性也可以设置在Action方法上面，以达到更细粒度的控制缓存。
代码片段
public class HomeController : Controller
{
[OutputCache(Duration = 10)]
// GET: Home
public string Index()
{
return DateTime.Now.ToString();
}
}
此时，只有Index的页面进行了缓存。
WebConfig
如果多个控制器或者Action使用相同的缓存配置，可以在配置文件中进行统一配置。
<system.web>
<caching>
<outputCacheSettings>
<outputCacheProfiles >
<add name=‘myoutputcache‘ duration=‘10‘/>
</outputCacheProfiles>
</outputCacheSettings>
</caching>
<compilation debug="true" targetFramework="4.5"/>
<httpRuntime targetFramework="4.5"/>
</system.web>
应用名称为myoutputcache的缓存
public class HomeController : Controller
{
[OutputCache(CacheProfile = "myoutputcache")]
// GET: Home
public string Index()
{
return DateTime.Now.ToString();
}
}
Note：
当控制器和Action同时使用了OutputCache特性时，以Action为主。
OutputCache参数
#region Assembly System.Web.Mvc.dll, v5.2.2.0
#endregion
using System;
using System.Web.UI;
namespace System.Web.Mvc
{
// Summary:
// Represents an attribute that is used to mark an action method whose output
// will be cached.
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = false)]
public class OutputCacheAttribute : ActionFilterAttribute, IExceptionFilter
{
// Summary:
// Initializes a new instance of the System.Web.Mvc.OutputCacheAttribute class.
public OutputCacheAttribute();
// Summary:
// Gets or sets the cache profile name.
//
// Returns:
// The cache profile name.
public string CacheProfile { get; set; }
//
// Summary:
// Gets or sets the child action cache.
//
// Returns:
// The child action cache.
public static System.Runtime.Caching.ObjectCache ChildActionCache { get; set; }
//
// Summary:
// Gets or sets the cache duration, in seconds.
//
// Returns:
// The cache duration.
public int Duration { get; set; }
//
// Summary:
// Gets or sets the location.
//
// Returns:
// The location.
public OutputCacheLocation Location { get; set; }
//
// Summary:
// Gets or sets a value that indicates whether to store the cache.
//
// Returns:
// true if the cache should be stored; otherwise, false.
public bool NoStore { get; set; }
//
// Summary:
// Gets or sets the SQL dependency.
//
// Returns:
// The SQL dependency.
public string SqlDependency { get; set; }
//
// Summary:
// Gets or sets the vary-by-content encoding.
//
// Returns:
// The vary-by-content encoding.
public string VaryByContentEncoding { get; set; }
//
// Summary:
// Gets or sets the vary-by-custom value.
//
// Returns:
// The vary-by-custom value.
public string VaryByCustom { get; set; }
//
// Summary:
// Gets or sets the vary-by-header value.
//
// Returns:
// The vary-by-header value.
public string VaryByHeader { get; set; }
//
// Summary:
// Gets or sets the vary-by-param value.
//
// Returns:
// The vary-by-param value.
public string VaryByParam { get; set; }
// Summary:
// Returns a value that indicates whether a child action cache is active.
//
// Parameters:
// controllerContext:
// The controller context.
//
// Returns:
// true if the child action cache is active; otherwise, false.
public static bool IsChildActionCacheActive(ControllerContext controllerContext);
//
// Summary:
// This method is an implementation of System.Web.Mvc.IActionFilter.OnActionExecuted(System.Web.Mvc.ActionExecutedContext)
// and supports the ASP.NET MVC infrastructure. It is not intended to be used
// directly from your code.
//
// Parameters:
// filterContext:
// The filter context.
public override void OnActionExecuted(ActionExecutedContext filterContext);
//
// Summary:
// This method is an implementation of System.Web.Mvc.IActionFilter.OnActionExecuting(System.Web.Mvc.ActionExecutingContext)
// and supports the ASP.NET MVC infrastructure. It is not intended to be used
// directly from your code.
//
// Parameters:
// filterContext:
// The filter context.
public override void OnActionExecuting(ActionExecutingContext filterContext);
//
// Summary:
// This method is an implementation of System.Web.Mvc.IExceptionFilter.OnException(System.Web.Mvc.ExceptionContext)
// and supports the ASP.NET MVC infrastructure. It is not intended to be used
// directly from your code.
//
// Parameters:
// filterContext:
// The filter context.
public void OnException(ExceptionContext filterContext);
//
// Summary:
// This method is an implementation of System.Web.Mvc.IResultFilter.OnResultExecuted(System.Web.Mvc.ResultExecutedContext)
// and supports the ASP.NET MVC infrastructure. It is not intended to be used
// directly from your code.
//
// Parameters:
// filterContext:
// The filter context.
public override void OnResultExecuted(ResultExecutedContext filterContext);
//
// Summary:
// Called before the action result executes.
//
// Parameters:
// filterContext:
// The filter context, which encapsulates information for using System.Web.Mvc.AuthorizeAttribute.
//
// Exceptions:
// System.ArgumentNullException:
// The filterContext parameter is null.
public override void OnResultExecuting(ResultExecutingContext filterContext);
}
}
常用的属性
CacheProfile：缓存使用的配置文件的缓存名称。
Duration：缓存时间，以秒为单位，这个除非你的Location=None，可以不添加此属性，其余时候都是必须的。
OutputCacheLocation：枚举类型，缓存的位置。当设置成None时，所有缓存将失效，默认为Any。
namespace System.Web.UI
{
// Summary:
// Specifies the valid values for controlling the location of the output-cached
// HTTP response for a resource.
public enum OutputCacheLocation
{
// Summary:
// The output cache can be located on the browser client (where the request
// originated), on a proxy server (or any other server) participating in the
// request, or on the server where the request was processed. This value corresponds
// to the System.Web.HttpCacheability.Public enumeration value.
Any = 0,
//
// Summary:
// The output cache is located on the browser client where the request originated.
// This value corresponds to the System.Web.HttpCacheability.Private enumeration
// value.
Client = 1,
//
// Summary:
// The output cache can be stored in any HTTP 1.1 cache-capable devices other
// than the origin server. This includes proxy servers and the client that made
// the request.
Downstream = 2,
//
// Summary:
// The output cache is located on the Web server where the request was processed.
// This value corresponds to the System.Web.HttpCacheability.Server enumeration
// value.
Server = 3,
//
// Summary:
// The output cache is disabled for the requested page. This value corresponds
// to the System.Web.HttpCacheability.NoCache enumeration value.
None = 4,
//
// Summary:
// The output cache can be stored only at the origin server or at the requesting
// client. Proxy servers are not allowed to cache the response. This value corresponds
// to the combination of the System.Web.HttpCacheability.Private and System.Web.HttpCacheability.Server
// enumeration values.
ServerAndClient = 5,
}
}
VaryByParam：用于多个输出缓存的字符串列表，并以分号进行分隔。默认时，该字符串与GET方法传递的参数或与POST方法传递的变量相对应。当被设置为多个参数时，输出缓存将会为每个参数都准备一个与之相对应的文档版本。可能值包括none，*，以及任何有效的查询串或POST参数名称。
结语
由于没找到缓存依赖mysql的办法，关于OutputCache的内容就先到这里。
关于缓存依赖的内容，可参考这篇文章
http://www.cnblogs.com/iamlilinfeng/p/4419362.html
时间： 2024-10-10 00:31:47