Calling Async Methods in Action Filters in MVC 5

Question

I\'m writing an Action Filter (inheriting from ActionFilterAttribute) which uses HttpClient to POST data to an external server in the OnResultExe

Answer 1

Yes, it's still true. Web API 2 has support for async action filters, but MVC 5 still does not. I was just personally frustrated by this not too long ago. For the time being, you will either need to run your async method as sync inside the action filter, or repeat the async code that you would have had in an action filter inside each action that requires it, which you then can run as async.

Answer 2

Some guy kind of 'back ported' it here

https://github.com/jdaigle/Hydrogen.Extensions.Mvc5

I haven't tried it and can't recommend it but if you're in transition to .NET Core it might be worth considering. Fortunately I managed to remove all async code from my extension - this time.