ASP.NET MVC 404错误处理

   <customErrors mode="On" defaultRedirect="Error">
       <error statusCode="404" redirect="Error404"/>
    </customErrors>
</system.web>

public class NotFoundHttpModule : IHttpModule
{
    public void Init(HttpApplication context)
    {
        context.EndRequest += OnEndRequest;
    }

    private void OnEndRequest(object sender, EventArgs e)
    {
        var app = (HttpApplication)sender;

        if (app.Response.StatusCode == 404)
        {
            // Handle the 404 error here.
        }
    }

    public void Dispose()
    {
    }
}

   <system.webServer>
       <modules>
            <add name="NotFoundHttpModule" type="Namespace.NotFoundHttpModule"/>
        </modules>
    </system.webServer>
</configuration>

public class NotFoundActionFilter : IActionFilter
{
    public void OnActionExecuting(ActionExecutingContext filterContext)
    {
    }

    public void OnActionExecuted(ActionExecutedContext filterContext)
    {
        if (filterContext.HttpContext.Response.StatusCode == 404)
        {
            // Handle the 404 error here.
        }
    }
}

public class MvcApplication : System.Web.HttpApplication
{
    protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
        RouteConfig.RegisterRoutes(RouteTable.Routes);
        BundleConfig.RegisterBundles(BundleTable.Bundles);

        GlobalFilters.Filters.Add(new NotFoundActionFilter());
    }
}