c# - 如何正确重试 HttpRequestMessage？

Question

我有一个向服务器发送 POST 请求的方法。该请求在 HttpRequestMessage 对象中定义。

然而，如果服务器返回一些可重试错误，我想重试，如下面的代码:

using (var request = new HttpRequestMessage(HttpMethod.Post, _endpoint))
{
    var requestPayload = Serialize(ingestionRequest);
    request.Content = new StringContent(requestPayload, Encoding.UTF8, JsonContentType);

    await _retryPolicy.ExecuteAsync(async () =>
    {
        // ReSharper disable once AccessToDisposedClosure
        using (var response = await _httpClient.SendAsync(request))
        {
            if (!response.IsSuccessStatusCode)
            {
                throw new IngestionException(response.StatusCode, response.ReasonPhrase);
            }
        }
    });
}

事实证明，HttpRequestMessage 不能发送多次，抛出以下异常:

The request message was already sent. Cannot send the same request message multiple times.

我怎样才能做到上面代码试图做的事情 - 同时保持代码简单和优雅？

Answer 1

尝试使用某种方式复制/克隆请求消息 like this answer .然后在下次重试时使用克隆的请求。有点像

if (!response.IsSuccessStatusCode)
{
  var oldRequest = request;
  request = request.Clone();
  oldRequest.Dispose();
  throw new IngestionException(response.StatusCode, response.ReasonPhrase);
}