问从托管在Azure中的Asp.net Core应用程序中获取“响应状态代码并不表示成功: 502 (坏网关)”

EN

public class ApiClientFactory
{
    private static Uri ApiUrl;
    private static Lazy<ApiClient> restClient = new Lazy<ApiClient>(
        () => new ApiClient(ApiUrl),
        LazyThreadSafetyMode.ExecutionAndPublication);

    static ApiClientFactory()
    {
        ApiUrl = new Uri(Convert.ToString(ConfigurationManager.AppSettings["WebAPIUrl"]));
    }

    public static ApiClient Instance
    {
        get
        {
            return restClient.Value;
        }
    }
}

public class ApiClient
{
   private readonly HttpClient _httpClient;
   private readonly Uri BaseEndPointUrl;

   public ApiClient(Uri baseEndPointUrl)
   {
       if (baseEndPointUrl == null)
           throw new ArgumentNullException("baseEndPointUrl");

       BaseEndPointUrl = baseEndPointUrl;
       _httpClient = new HttpClient();
       _httpClient.DefaultRequestHeaders.Add("Accept", "application/json");
       _httpClient.Timeout = new TimeSpan(0, 5, 0); //Timeout needed for few modules to get results from db.
   }

   private HttpContent CreateHttpContent<T>(T content)
   {
       var json = JsonConvert.SerializeObject(content, MicrosoftDateFormatSettings);
       return new StringContent(json, Encoding.UTF8, "application/json");
   }

   private static JsonSerializerSettings MicrosoftDateFormatSettings
   {
       get
       {
           return new JsonSerializerSettings
           {
               DateFormatHandling = DateFormatHandling.MicrosoftDateFormat
           };
       }
   }

   public async Task<T1> PostAsync<T1, T2>(string url, T2 content, string token)
   {
       try
       {
           _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
           var response = await _httpClient.PostAsync(url, CreateHttpContent<T2>(content));

           if (response.StatusCode == HttpStatusCode.InternalServerError){
               var exception = await response.Content.ReadAsStringAsync();
               throw new Exception(exception);
           }
           response.EnsureSuccessStatusCode();
           var data = await response.Content.ReadAsStringAsync();

           return JsonConvert.DeserializeObject<T1>(data);
       }
       catch (Exception ex){throw ex;}
   }
}