我正在使用一个自定义类，它分别为移动页面和普通页面输出 cche。我只缓存索引页。它在使用索引页面缓存时非常有效。但是与子操作一起使用时，会引发以下错误：
Server Error in '/' Application.
Unable to cast object of type 'System.IO.StringWriter' to type 'System.Web.HttpWriter'.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.InvalidCastException: Unable to cast object of type 'System.IO.StringWriter' to type 'System.Web.HttpWriter'.
Source Error:
Line 82: sw = new StringWriter(sb);
Line 83: tw = new HtmlTextWriter(sw);
Line 84: output = (HttpWriter)filterContext.RequestContext.HttpContext.Response.Output;
Line 85: filterContext.RequestContext.HttpContext.Response.Output = tw;
Line 86: }
Source File: H:\Yazılımlar\Haber Sitesi v2\HaberSitesiV2\HaberSitesiV2\Filters\CustomCacheAttribute.cs Line: 84
Stack Trace:
[InvalidCastException: Unable to cast object of type 'System.IO.StringWriter' to type 'System.Web.HttpWriter'.]
HaberSitesiV2.Filters.CustomCacheAttribute.OnActionExecuting(ActionExecutingContext filterContext) in H:\Yazılımlar\Haber Sitesi v2\HaberSitesiV2\HaberSitesiV2\Filters\CustomCacheAttribute.cs:84
System.Web.Mvc.Async.AsyncControllerActionInvoker.InvokeActionMethodFilterAsynchronously(IActionFilter filter, ActionExecutingContext preContext, Func`1 nextInChain) +69
System.Web.Mvc.Async.<>c__DisplayClass3b.<BeginInvokeActionMethodWithFilters>b__35() +21
System.Web.Mvc.Async.AsyncControllerActionInvoker.InvokeActionMethodFilterAsynchronously(IActionFilter filter, ActionExecutingContext preContext, Func`1 nextInChain) +489
System.Web.Mvc.Async.<>c__DisplayClass3b.<BeginInvokeActionMethodWithFilters>b__35() +21
System.Web.Mvc.Async.AsyncControllerActionInvoker.InvokeActionMethodFilterAsynchronously(IActionFilter filter, ActionExecutingContext preContext, Func`1 nextInChain) +489
System.Web.Mvc.Async.<>c__DisplayClass3b.<BeginInvokeActionMethodWithFilters>b__35() +21
System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__31(AsyncCallback asyncCallback, Object asyncState) +191
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +130
System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters, AsyncCallback callback, Object state) +197
System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__1e(AsyncCallback asyncCallback, Object asyncState) +446
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +130
System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeAction(ControllerContext controllerContext, String actionName, AsyncCallback callback, Object state) +302
System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__17(AsyncCallback asyncCallback, Object asyncState) +30
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +130
System.Web.Mvc.Controller.BeginExecuteCore(AsyncCallback callback, Object state) +382
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +130
System.Web.Mvc.Controller.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +317
System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +15
System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__2(AsyncCallback asyncCallback, Object asyncState) +71
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +130
System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +249
System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state) +50
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16
System.Web.Mvc.<>c__DisplayClass7.<BeginProcessRequest>b__6() +31
System.Web.Mvc.ServerExecuteHttpHandlerWrapper.Wrap(Func`1 func) +27
System.Web.Mvc.ServerExecuteHttpHandlerAsyncWrapper.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +98
System.Web.HttpServerUtility.ExecuteInternal(IHttpHandler handler, TextWriter writer, Boolean preserveForm, Boolean setPreviousPage, VirtualPath path, VirtualPath filePath, String physPath, Exception error, String queryStringOverride) +2019
System.Web.HttpServerUtility.Execute(IHttpHandler handler, TextWriter writer, Boolean preserveForm, Boolean setPreviousPage) +76
System.Web.HttpServerUtility.Execute(IHttpHandler handler, TextWriter writer, Boolean preserveForm) +28
System.Web.HttpServerUtilityWrapper.Execute(IHttpHandler handler, TextWriter writer, Boolean preserveForm) +19
System.Web.Mvc.Html.ChildActionExtensions.ActionHelper(HtmlHelper htmlHelper, String actionName, String controllerName, RouteValueDictionary routeValues, TextWriter textWriter) +483
System.Web.Mvc.Html.ChildActionExtensions.Action(HtmlHelper htmlHelper, String actionName, String controllerName, RouteValueDictionary routeValues) +83
System.Web.Mvc.Html.ChildActionExtensions.Action(HtmlHelper htmlHelper, String actionName, String controllerName) +10
ASP._Page_Views_Anasayfa_Index_cshtml.Execute() in h:\Yazılımlar\Haber Sitesi v2\HaberSitesiV2\HaberSitesiV2\Views\Anasayfa\Index.cshtml:29
System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +197
System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +97
System.Web.WebPages.StartPage.RunPage() +17
System.Web.WebPages.StartPage.ExecutePageHierarchy() +62
System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +76
System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +260
System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +115
System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +295
System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) +13
System.Web.Mvc.<>c__DisplayClass1a.<InvokeActionResultWithFilters>b__17() +23
System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) +242
System.Web.Mvc.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() +21
System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) +242
System.Web.Mvc.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() +21
System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) +177
System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +89
System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +102
System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +43
System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +14
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +57
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +47
System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +25
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +47
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9629708
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.17929
我的课是跟随。
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Web;
using System.Web.Caching;
using System.Web.Mvc;
using System.Text.RegularExpressions;
using System.Reflection;
using System.Web.UI;
using System.Web.WebPages;
namespace HaberSitesiV2.Filters
{
public enum CachePolicy
{
NoCache = 0,
Client = 1,
Server = 2,
ClientAndServer = 3
}
public class CustomCacheAttribute : ActionFilterAttribute
{
#region Public properties
public string VaryByParam { get; set; }
public CachePolicy CachePolicy { get; set; }
#endregion
#region Private members
private HtmlTextWriter tw;
private StringWriter sw;
private StringBuilder sb;
private HttpWriter output;
private bool cacheHitNormal = false;
private bool cacheHitMobile = false;
#endregion
#region ActionFilterAttribute overrides
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
// Server-side caching?
if (CachePolicy == CachePolicy.Server || CachePolicy == CachePolicy.ClientAndServer)
{
if (filterContext.HttpContext.Application["cacheSql"] != null)
{
// Fetch cached data
string key = GenerateKey(filterContext);
object cachedData = HttpContext.Current.Cache.Get(key);
if (cachedData != null)
{
// cache hit
if (filterContext.HttpContext.GetOverriddenBrowser().IsMobileDevice)
cacheHitMobile = true;
else
cacheHitNormal = true;
// Return cached data
filterContext.HttpContext.Response.Write(cachedData);
filterContext.Result = new EmptyResult();
}
else
{
// Cache not hit.
if (filterContext.HttpContext.GetOverriddenBrowser().IsMobileDevice)
cacheHitMobile = false;
else
cacheHitNormal = false;
//
sb = new StringBuilder();
sw = new StringWriter(sb);
tw = new HtmlTextWriter(sw);
output = (HttpWriter)filterContext.RequestContext.HttpContext.Response.Output;
filterContext.RequestContext.HttpContext.Response.Output = tw;
}
}
}
}
public override void OnResultExecuted(ResultExecutedContext filterContext)
{
// Server-side caching?
if (CachePolicy == CachePolicy.Server|| CachePolicy == CachePolicy.ClientAndServer)
{
if (filterContext.HttpContext.Application["cacheSql"] != null)
{
if (filterContext.HttpContext.GetOverriddenBrowser().IsMobileDevice ? !cacheHitMobile : !cacheHitNormal)
{
int duration = 0;
duration = Convert.ToInt32(filterContext.HttpContext.Application["cacheSql"]);
//response processing
output.Write(sb.ToString());
// Add data to cache
HttpContext.Current.Cache.Insert(
GenerateKey(filterContext),
sb.ToString(),
null,
DateTime.Now.AddMinutes(duration),
Cache.NoSlidingExpiration,
CacheItemPriority.Normal,
null);
}
}
}
}
#endregion
#region Helper methods
private string GenerateKey(ControllerContext filterContext)
{
StringBuilder cacheKey = new StringBuilder();
// Controller + action
cacheKey.Append(filterContext.Controller.GetType().FullName);
if (filterContext.RouteData.Values.ContainsKey("action"))
{
cacheKey.Append("_");
cacheKey.Append(filterContext.RouteData.Values["action"].ToString());
}
// Variation by parameters
List<string> varyByParam = VaryByParam.Split(';').ToList();
if (!string.IsNullOrEmpty(VaryByParam))
{
foreach (KeyValuePair<string, object> pair in filterContext.RouteData.Values)
{
if (VaryByParam == "*" || varyByParam.Contains(pair.Key))
{
cacheKey.Append("_");
cacheKey.Append(pair.Key);
cacheKey.Append("=");
cacheKey.Append(pair.Value.ToString());
}
}
}
cacheKey.Append("_");
cacheKey.Append(filterContext.HttpContext.GetOverriddenBrowser().IsMobileDevice ? "mobil" : "normal");
return cacheKey.ToString();
}
#endregion
}
}