IActionFilter de ASP.Net MVC 5.2.3

IActionFilter.cs

// Assembly Microsoft.AspNet.Mvc.5.2.3
namespace System.Web.Mvc
{
  /// <summary>
  /// Defines the methods that are used in an action filter.
  /// </summary>
  public interface IActionFilter
  {
    /// <summary>
    /// Called before an action method executes.
    /// </summary>
    /// <param name="filterContext">The filter context.</param>
    void OnActionExecuting(ActionExecutingContext filterContext);

    /// <summary>
    /// Called after the action method executes.
    /// </summary>
    /// <param name="filterContext">The filter context.</param>
    void OnActionExecuted(ActionExecutedContext filterContext);
  }
}