o_19mgorv9t13a3ko71fev19l81mqa.pdf

execute the result. You can see how I applied this filter to the Home controller in Listing 18-38.
Listing 18-38. Applying the Result Filter in the HomeController.cs File
...
[ProfileAction]
[ProfileResult]
public string FilterTest() {
return "This is the ActionFilterTest action";
}
...
Figure 18-9 shows the effect of starting the application and navigating to the /Home/FilterTest URL. You can see
that both filters have added data to the response sent to the browser. The output from the result filter is shown after the result
from the action method, of course, since the OnResultExecuted method cannot be executed by the MVC Framework
until the result has been properly dealt with—which, in this case, means inserting a string value into the result.
Figure 18-9. The effect of applying a result filter
Using the Built-in Action and Result Filter Class
The MVC Framework includes a built-in class that can be derived to create a class that is both an action and result filter. The
class, called ActionFilterAttribute, is shown in Listing 18-39.
Listing 18-39. The ActionFilterAttribute Class
public abstract class ActionFilterAttribute : FilterAttribute,
IActionFilter,
IResultFilter{
public virtual void OnActionExecuting(ActionExecutingContext
filterContext) {
}
public virtual void OnActionExecuted(ActionExecutedContext
filterContext) {
}
public virtual void OnResultExecuting(ResultExecutingContext
filterContext) {
}
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