从 WebClient 获取响应 Headers

Question

我正在尝试使用 WebClient 上传文件，但似乎无法找到获得响应的方法 headers 文件上传后我正在使用 this Microsoft example得到 headers，但它只是 returns null。我的代码如下所示：

public void UploadPart(string filePath, string preSignedUrl)
{
   WebClient wc = new();
   wc.UploadProgressChanged += WebClientUploadProgressChanged;
   wc.UploadFileCompleted += WebClientUploadCompleted;
   wc.UploadFileAsync(new Uri(preSignedUrl), "PUT", filePath);

   // Obtain the WebHeaderCollection instance containing the header name/value pair from the response.
   WebHeaderCollection myWebHeaderCollection = wc.ResponseHeaders;

   System.Diagnostics.Debug.WriteLine(myWebHeaderCollection);
}

我可以确认 headers 存在，因为我能够在另一种方法中使用 HttpWebResponse 上传实现来获取它们。

Answer 1

方法应该这样写

public Task UploadPart(string filePath, string preSignedUrl)
{
   WebClient wc = new();
   wc.UploadProgressChanged += WebClientUploadProgressChanged;
   wc.UploadFileCompleted += WebClientUploadCompleted;
   await wc.UploadFileAsync(new Uri(preSignedUrl), "PUT", filePath);

   // Obtain the WebHeaderCollection instance containing the header name/value pair from the response.
   WebHeaderCollection myWebHeaderCollection = wc.ResponseHeaders;

   System.Diagnostics.Debug.WriteLine(myWebHeaderCollection);
}

将 void 替换为 Task。在 UploadFileAsyn 中使用 await，因为它可能无需请求就可以完成代码跳转到下一行。

从 WebClient 获取响应 Headers

Get Response Headers From WebClient

c#

.net-core

webclient