/// <inheritdoc/> public async Task <string> DownloadFrom(Uri url) { uint attempt = 1; while (true) { try { var request = httpClient.GetStringAsync(url); return(await request); } catch (HttpRequestException ex) when(ex.Message.Contains(/*HTTP Fehler*/ " 403 ")) { if (attempt <= _maxRetries) { System.Threading.Thread.Sleep( RetryStrategy.CalculateExponentialBackoff(timeSlotForRetry, attempt) ); ++attempt; continue; } throw new Exception($"Das Abrufen von Hypertext aus der URL {url} is gescheitert!", ex); } } }