asp.net-mvc - 属性的 OnActionExecuted 方法是否总是执行？

Question

我搜索了高低，似乎找不到直接的答案。

如果我有自定义属性/过滤器，OnActionExecuted 是否会出现？方法总是被调用？即使有异常抛出？

Answer 1

至少在 MVC 5 中，@tvanfosson 的答案不再正确。这也可能适用于早期版本。
OnActionExecuted总是被调用并且可以通过 filterContext.Exception 访问抛出的异常.

一个 Action 中有异常的测试用例:

public class HomeController
    : Controller
{
    public ActionResult Index()
    {
        throw new Exception("Index");
    }
}

public class FilterConfig
{
    public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {
        filters.Add(new Foo());
        filters.Add(new Bar());
    }
}

public class Foo
    : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        Debug.WriteLine($"{nameof(Foo)}.{nameof(OnActionExecuting)}");
        base.OnActionExecuting(filterContext);
    }

    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        Debug.WriteLine($"{nameof(Foo)}.{nameof(OnActionExecuted)}");
        Debug.WriteLine($"Has exception: {filterContext.Exception != null}");
        base.OnActionExecuted(filterContext);
    }
}

public class Bar
    : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        Debug.WriteLine($"{nameof(Bar)}.{nameof(OnActionExecuting)}");
        base.OnActionExecuting(filterContext);
    }

    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        Debug.WriteLine($"{nameof(Bar)}.{nameof(OnActionExecuted)}");
        Debug.WriteLine($"Has exception: {filterContext.Exception != null}");
        base.OnActionExecuted(filterContext);
    }
}

输出:

Bar.OnActionExecuting
Foo.OnActionExecuting
Exception thrown: 'System.Exception' in WebApplication1.dll
Foo.OnActionExecuted
Has exception: True
Bar.OnActionExecuted
Has exception: True

过滤器中有异常的测试用例

public class HomeController
    : Controller
{
    public ActionResult Index()
    {
        return new HttpStatusCodeResult(200);
    }
}

public class FilterConfig
{
    public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {
        filters.Add(new Foo());
        filters.Add(new Bar());
    }
}

public class Foo
    : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        Debug.WriteLine($"{nameof(Foo)}.{nameof(OnActionExecuting)}");
        base.OnActionExecuting(filterContext);
    }

    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        Debug.WriteLine($"{nameof(Foo)}.{nameof(OnActionExecuted)}");
        Debug.WriteLine($"Has exception: {filterContext.Exception != null}");
        throw new Exception("Foo");
        base.OnActionExecuted(filterContext);
    }
}

public class Bar
    : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        Debug.WriteLine($"{nameof(Bar)}.{nameof(OnActionExecuting)}");
        base.OnActionExecuting(filterContext);
    }

    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        Debug.WriteLine($"{nameof(Bar)}.{nameof(OnActionExecuted)}");
        Debug.WriteLine($"Has exception: {filterContext.Exception != null}");
        base.OnActionExecuted(filterContext);
    }
}

输出:

Bar.OnActionExecuting
Foo.OnActionExecuting
Foo.OnActionExecuted
Has exception: False
Exception thrown: 'System.Exception' in WebApplication1.dll
Bar.OnActionExecuted
Has exception: True