asp.net MVC key Tutorial First anniversary version Sixth filters filter filter

In ASP.NETMVC you can use the filter function when you have the following and similar requirements

Determine whether or not a login or user right

Decision output Caching

Anti-Theft chain

Anti-Spider

Localization and internationalization settings

Implementing Dynamic Action

Filter is a declarative programming method that can only be limited to an action (or its controller) in ASP.net mvc.

The filter is inherited from the ActionFilterAttribute abstract class and can override the void OnActionExecuting (ActionExecutingContext) and

void onactionexecuted (ActionExecutedContext)

and void Onresultexecuting (ResultExecutingContext) and

void onresultexecuted (ResultExecutedContext)

OnActionExecuting is the action that is performed before the action, and onactionexecuted is the actions performed by action

And onresultexecuting is to parse actionresult before execution, onresultexecuted is parse actionresult after execution.

The filter applied to action

Let me give you an example to see the order in which it is executed.

First we build a Filter, called Testfilter.

public　class　TestFilter　:　 ActionFilterAttribute
{
public　override　void　OnActionExecuting (ActionExecutingContext　filterContext)
{
filterContext.HttpContext.Session ["temp"]　+=　"TestFilter　OnActionExecuting<br/>";
}

public　override　void　OnActionExecuted(ActionExecutedContext　 filterContext)
{
filterContext.HttpContext.Session["temp"]　+=　 "TestFilter　OnActionExecuted<br/>";
}
public　override　 void　OnResultExecuting(ResultExecutingContext　filterContext)
{
filterContext.HttpContext.Session["temp"]　+=　"TestFilter　 OnResultExecuting<br/>";
}

public　override　void　 OnResultExecuted(ResultExecutedContext　filterContext)
{
filterContext.HttpContext.Session["temp"]　+=　"TestFilter　 OnResultExecuted<br/>";
}
}

Then create an action:

[TestFilter]//将此Filter应用于Action
public　 ActionResult　filteraction()
{
return　View();
}