In what order are filters executed in asp.net mvc

问题:

In MVC we can decorate action methods with different filters like

[HttpPost]
[Authorize]
public ActionResult mymethod(){}

HttpPost derives from MethodSelectorAttribute (probably indirectly) and the Authorize attribute inherits from ActionFilterAttribute.

My question is: in which order are they executed in the MVC request pipeline? I tried to go search in MVC source code but failed to find the relevant code bits.

回答1:

Filters run in the following order:

1. Authorization filters
2. Action filters
3. Response filters
4. Exception filters

For example, authorization filters run first and exception filters run last. Within each filter type, the Order value specifies the run order. Within each filter type and order, the Scope enumeration value specifies the order for filters. This enumeration defines the following filter scope values (in the order in which they run):

1. First
2. Global
3. Controller
4. Action
5. Last

Extracted from MSDN

回答2:

To save you some time, this is how you set the order:

[MyCustomContextFilter(Order=1)]

The index is 0 based, so you can do 0, 1, 2, etc...

It should be noted that just because a filter is on the base class doesn't tell MVC to apply it first :(.