C# HttpClient.PostAsync 不返回或抛出错误

Question

我有一个 Windows 服务发出 HTTP POST 请求。 REST 端点正在工作，并且已单独测试。调用PostAsync 后，调试器不会继续或抛出错误。导致这种行为的可能问题是什么？下面是sn-p发送POST请求的代码，

编辑：我已将其更改为 async-await 并使用 ConfigureAWait，但这并没有解决问题。我需要知道是什么导致函数没有返回任何值。

HttpClientHandler handler = GetCookieHandler();
using(HttpClient client = new HttpClient(handler)) {
    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("basic", accessToken);

    client.DefaultRequestHeaders.Add("UniqueId", _configReader.UniqueId);

    SetRequestCookie(handler);

    string jsonContent = JsonConvert.SerializeObject(content);

    HttpResponseMessage response = client.PostAsync(url, new StringContent(jsonContent, Encoding.UTF8, "application/json")).Result;

    SaveCookie(handler, response.RequestMessage.RequestUri);

    if (response.StatusCode == HttpStatusCode.Unauthorized) {
        var customerJsonString = response.Content.ReadAsStringAsync().Result;

        Error data = JsonConvert.DeserializeObject < Error > (customerJsonString);

        switch (data.ErrorCode) {
        case AccessTokenValidationCodes.ExpiredOrInvalidDateTime:
            logger.Warn("Expired AccessToken");
            break;

        default:
            break;
        }
    }

    if (response.StatusCode == HttpStatusCode.Unauthorized) {
        logger.Error("Request :{0}, AccessToken {1}  response Unauthorized", apirUrl, accessToken);
        return null;
    }
    if (response.StatusCode == HttpStatusCode.InternalServerError) {
        logger.Warn("Request response InternalServerError");
        return null;
    }
    return response;
}

Answer 1

除了我的重复评论，您需要阅读最后的回复。目前，您仅在未经授权的情况下执行此操作，但无论如何您都应该阅读以结束。确保您使用the advice from the comment，包括异步等待，以及：

将 ReadAsString 行移出并确保它对端点的所有调用都运行。

 HttpResponseMessage response = client.PostAsync(url, new StringContent(jsonContent, Encoding.UTF8, "application/json")).Result; 
 var customerJsonString = response.Content.ReadAsStringAsync().Result;

你的代码

if (response.StatusCode == HttpStatusCode.Unauthorized) {
        var customerJsonString = response.Content.ReadAsStringAsync().Result;

        Error data = JsonConvert.DeserializeObject < Error > (customerJsonString);

        switch (data.ErrorCode) {    
            case AccessTokenValidationCodes.ExpiredOrInvalidDateTime:
                logger.Warn("Expired AccessToken");
                break;

            default:
                break;
        }