总是输出特定的HTML吗？

Question

I'm facing an issue with ASP .NET MVC. I'm working on a technique to allow a session from recovering after it has died (expired). For this technique to work, I need a way of being able to write to the response after a controller's action method has been invoked.

Which approach would be the best? Is there an action-filter for this?

Answer 1

If you want to use an attribute based approach, derive from ActionFilterAttribute and override either OnActionExecuted (run after the action has been executed, but before the result has been executed) or OnResultExecuted (run after the result has been executed, eg after the view has been rendered).

If you're not going the attribute way, implement IActionFilter or IResultFilter and implement the methods mentioned above.

You can access the output writer/output stream via filterContext.HttpContext.Response.Output or filterContext.HttpContext.Response.OutputStream respectively.

Answer 2

Create a filter that will occur after an action is excuted, like this:

using System;

namespace Sample
{
    [AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
    public class SampleFilter : ActionFilterAttribute
    {
        public override void OnActionExecuted(ActionExecutedContext filterContext)
        {

            base.OnActionExecuted(filterContext);
        }
    }
}

Then decorate your action(s) like this:

[SampleFilter]
public virtual ActionResult Index()
{
    return View();
}