ASP.NET Core ActionFilter 中是否提供 CancellationToken？

Question

I could inject CancellationToken into ASP.NET Core action method, but I would instead prefer to work with it using action filter. How to get access to cancellation token while implementing IAsyncActionFilter ? My method should not have it as a parameter then.

Answer 1

You already post a link to a very good article, which contains a small hint where you can get this token.

MVC will automatically bind any CancellationToken parameters in an action method to the HttpContext.RequestAborted token, using the CancellationTokenModelBinder .

So, all you have to do is acquire that token in your action filter:

public class CustomActionFilterAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext context)
    {
        var cancellationToken = context.HttpContext.RequestAborted;
        // rest of your code
    }
}