Question

在阅读/浏览HttpClient之后，我觉得这个组件不适合将大文件或内容上传到REST服务。

似乎如果上传超过建立的超时，传输将失败。是否有意义？这个超时是什么意思？
获取进度信息似乎很难或需要附加组件。

所以我的问题是：是否有可能在没有太多麻烦的情况下解决这两个问题？否则，在处理大型内容和REST服务时，最好的方法是什么？

Answer 1

是的，如果上传时间超过TimeOut，则上传将失败。这是HttpClient的限制。这个问题的最有效解决方案是Thomas Levesque written an article about {{}} {{}} {}} {}} {{}}您必须使用HttpWebRequest代替HttpClient。
如果要获取进度消息，请将文件作为FileStream打开并手动迭代，将增量字节复制到（上传）请求流中。随着时间的推移，您可以计算相对于文件大小的进度。

TL的代码示例。 Be sure to read the article though!：

long UploadFile(string path, string url, string contentType)
{
    // Build request
    var request = (HttpWebRequest)WebRequest.Create(url);
    request.Method = WebRequestMethods.Http.Post;
    request.AllowWriteStreamBuffering = false;
    request.ContentType = contentType;
    string fileName = Path.GetFileName(path);
    request.Headers["Content-Disposition"] = string.Format("attachment; filename=\"{0}\"", fileName);

    try
    {
        // Open source file
        using (var fileStream = File.OpenRead(path))
        {
            // Set content length based on source file length
            request.ContentLength = fileStream.Length;

            // Get the request stream with the default timeout
            using (var requestStream = request.GetRequestStreamWithTimeout())
            {
                // Upload the file with no timeout
                fileStream.CopyTo(requestStream);
            }
        }

        // Get response with the default timeout, and parse the response body
        using (var response = request.GetResponseWithTimeout())
        using (var responseStream = response.GetResponseStream())
        using (var reader = new StreamReader(responseStream))
        {
            string json = reader.ReadToEnd();
            var j = JObject.Parse(json);
            return j.Value<long>("Id");
        }
    }
    catch (WebException ex)
    {
        if (ex.Status == WebExceptionStatus.Timeout)
        {
            LogError(ex, "Timeout while uploading '{0}'", fileName);
        }
        else
        {
            LogError(ex, "Error while uploading '{0}'", fileName);
        }
        throw;
    }
}

发送大文件/内容时HttpClient存在缺陷吗？

1 个答案: