Convert async to sync for HttpClient.SendAsync

I want to use a REST-call like this:

private async Task<HttpResponseMessage> SendRequestHelperAsync(HttpRequestMessage message, CancellationToken ct)
        {
            var response = await HttpClient.SendAsync(message, ct).ConfigureAwait(false);
            return response;
        }

from a non-async method. When I use it like this:

var response = SendRequestHelperAsync(message, ct).Result;

it gets stuck. When I use it directly, it gets stuck as well:

HttpResponseMessage response = HttpClient.SendAsync(message, ct).Result;

When I was looking for some solution, I came across using a task like this:

var task = Task.Run(async () => { await SendRequestHelperAsync(message, ct); });

but then how do I get the result back?

(I am using it from .Net Framework 4.8, WinForms Application.)

> I want to use [async code] from a non-async method.

The best answer is "don't". Instead, go async all the way.

You could use Task.Run as a workaround; this is the thread pool hack, which will work in this specific case (warning: it does not work in every case, specifically, if the code in the Task.Run delegate accesses UI elements, then this hack will not work). The thread pool hack supports return types, as such:

var response = Task.Run(async () => await SendRequestHelperAsync(message, ct))
    .GetAwaiter().GetResult();

However, the best answer is still "don't". The fact that you're deadlocking (as explained in detail on my blog) implies that this code is being run on the UI thread, and the solution is attempting to block the UI thread on a network request. Blocking the UI thread is a poor user experience.

Instead, the best solution is to redesign the UI so that no blocking is necessary. This is usually done by adding some kind of spinner or "loading..." UI element, and then updating the UI when the asynchronous operation completes.