Redirect from exception filter

Question

I'm using ASP.NET Core. One of my controllers calls into services which throw various exceptions. I want to handle them in an exception filter (not middleware).

public class MyHandlerAttribute : ExceptionFilterAttribute
{
    public override void OnException(ExceptionContext c)
    {
      if (c.Exception is FooException) {
          // redirect with arguments to here
      } 
      else if (c.Exception is FooException) {
          // redirect with arguments to there
      }
      else {
          // redirect to main error action without arguments, as 500
      }
      base.OnException(c);
    }
}

Unlike action filters, an exception filter doesn't give me access to the Controller, so I can't do a c.Result = controller.RedirectTo...().

So how do I redirect to my error action?

Answer 1

The HttpContext is exposed on the ExceptionContext, so you can use it for the redirection.

context.HttpContext.Response.Redirect("...");

There is also a Result property, but I don't know if it'll be interpreted after the execution of the filter. It's worth a try though:

context.Result = new RedirectResult("...");

If it works, it should also work with RedirectToActionResult or RedirectToRouteResult.