Using Polly to Retry After HttpStatusCode.Unauthorized

Question

I am calling an external API and want to deal with the event that the call returns Unauthorized HttpResponseMessage. When this happens, I want to update the access token and make the call again.

I am trying to use Pollywith the following code:

    public async Task<HttpResponseMessage> MakeGetRequestAsync()
    {
        var retryPolicy = Policy
            .HandleResult<HttpResponseMessage>(r => r.StatusCode == HttpStatusCode.Unauthorized)
            .Retry(1, (exception, retryCount) =>
            {
                RefreshAccessToken();
            });

        var result = await retryPolicy.ExecuteAsync(() => CallApiAsync());

        return result;
    }


    private async Task<HttpResponseMessage> CallApiAsync()
    {
        var url = Options.ResourceSandboxUrl;

        var httpClient = new HttpClient();
        SetRequestHeaders(httpClient);
        var response = await httpClient.GetAsync(url);

        response.StatusCode = HttpStatusCode.Unauthorized;
        return response;
    }

I set breakpoints in the statement ExecuteAsyncand in DoSomethingAsync- when passing through ExecuteAsync DoSomethingAsyncit is not called and control returns to a function calledMakeGetRequestAsync

I don’t understand why it’s DoSomethingAsyncnot called - can someone help me with what I am trying to achieve?

I looked at the Polly documentation and Polly's questions about the stack overflow, but I can't figure out what is going on.

Answer 1

ExecuteAsync(), .RetryAsync(...), .Retry(...).

, .ExecuteAsync(...) .Retry(...) [ ] .ExecuteAsync(...) [ ]. , CallApiAsync() . MakeGetRequestAsync()

: !

Answer 2

async .net, await,

• , , ,

• , , , ,