ASP.NET MVC ActionFilterAttribute的执行顺序

http://diaosbook.com/Post/2014/6/3/execution-order-of-actionfilter-aspnet-mvc

ASP.NET MVC里面我们要自定义ActionFilter的时候会发现有4个方法可以override：OnActionExecuting，OnActionExecuted，OnResultExecuting，OnResultExecuted。他们分别在什么时候执行一直是困扰人类的一个问题。我代表人类做了一个简单的实验：

首先自定义一个ActionFilter，每个方法执行的时候都在VS的OUTPUT窗口输出信息：

public class TestActionFilter : ActionFilterAttribute { public override void OnActionExecuting(ActionExecutingContext filterContext) { Debug.WriteLine("OnActionExecuting"); base.OnActionExecuting(filterContext); } public override void OnActionExecuted(ActionExecutedContext filterContext) { Debug.WriteLine("OnActionExecuted"); base.OnActionExecuted(filterContext); } public override void OnResultExecuting(ResultExecutingContext filterContext) { Debug.WriteLine("OnResultExecuting"); base.OnResultExecuting(filterContext); } public override void OnResultExecuted(ResultExecutedContext filterContext) { Debug.WriteLine("OnResultExecuted"); base.OnResultExecuted(filterContext); } }

Controller里为了搞清执行顺序，也需要输出：

[TestActionFilter] public ActionResult Index() { Debug.WriteLine("Before return View()"); return View(); }

最后是View：

@{ Debug.WriteLine("Hello from Index.cshtml"); }

执行结果是这样的，有图有JJ：

1. OnActionExecuting

2. Before return View()

3. OnActionExecuted

4. OnResultExecuting

5. Hello from Index.cshtml

6. OnResultExecuted