public async Task <bool> Upload(IFormFile formFile) { // full path to file in temp location var filePath = Path.GetTempFileName(); if (formFile.Length > 0) { using (var stream = new FileStream(filePath, FileMode.Create)) { await formFile.CopyToAsync(stream); string content = String.Empty; using (StreamReader streamReader = new StreamReader(stream, Encoding.UTF8)) { stream.Seek(0, SeekOrigin.Begin); while ((content = streamReader.ReadLine()) != null) { cities.Add(content.Trim()); } } } } foreach (var city in cities) { if (Startup.OpenAPIIdMappings.ContainsKey(city)) { listCityIds.Add(Startup.OpenAPIIdMappings[city]); } else { return(false); } } var resultString = _apiCient.APICall(cities); if (String.IsNullOrEmpty(resultString)) { return(false); } GenerateFiles(resultString); return(true); }