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