[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = true)]
    public abstract class ActionFilterAttribute : FilterAttribute, IActionFilter, IFilter
    {
        // 摘要:
        //     Initializes a new instance of the System.Web.Http.Filters.ActionFilterAttribute
        //     class.
        protected ActionFilterAttribute();

        // 摘要:
        //     Occurs after the action method is invoked.
        //
        // 参数:
        //   actionExecutedContext:
        //     The action executed context.
        public virtual void OnActionExecuted(HttpActionExecutedContext actionExecutedContext);
        public virtual Task OnActionExecutedAsync(HttpActionExecutedContext actionExecutedContext, CancellationToken cancellationToken);
        //
        // 摘要:
        //     Occurs before the action method is invoked.
        //
        // 参数:
        //   actionContext:
        //     The action context.
        public virtual void OnActionExecuting(HttpActionContext actionContext);
        public virtual Task OnActionExecutingAsync(HttpActionContext actionContext, CancellationToken cancellationToken);
    }