namespace FirstMvcDemo.Filter
{
    public class TestFilter : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            //如果要使用ViewBag或者ViewData等控制器中的内容，则使用方法中的参数filterContext.Controller
            filterContext.Controller.ViewBag.TestData = "内容1";
            filterContext.Controller.ViewData["TestData"] = "内容2";
            HttpContext.Current.Response.Write("正要准备执行Action的时候但还未执行时执行");
        }

        public override void OnActionExecuted(ActionExecutedContext filterContext)
        {
            HttpContext.Current.Response.Write("Action执行时但还未返回结果时执行");
        }

        public override void OnResultExecuting(ResultExecutingContext filterContext)
        {
            HttpContext.Current.Response.Write("OnResultExecuting也和OnActionExecuted一样，但前者是在后者执行完后才执行");
        }

        public override void OnResultExecuted(ResultExecutedContext filterContext)
        {
            HttpContext.Current.Response.Write("Action执行完后将要返回ActionResult的时候执行");
        }
    }
}

[TestFilter]
public ActionResult Home() 
{
    return View();
}