如何通过HttpClient以小写形式设置“Connection: keep-alive”标头？

我有一个任务，需要能够以与 Firefox 浏览器相同的方式发送 Connection: keep-alive 标头（请注意，keep-alive 必须全部小写）：

"Connection: keep-alive"

但是，我没有运气使用 HttpClient 实现它。无论我尝试什么，请求总是有

"Connection: Keep-Alive"

这是一个示例代码：

var client = new HttpClient();
var request = new HttpRequestMessage()
{
    RequestUri = new Uri("http://www.someURI.com"),
    Method = HttpMethod.Get,
};
request.Headers.Connection.Clear(); // No need to do it as it is empty anyway
request.Headers.Connection.Add("keep-alive"); // Still results in "Keep-Alive"
var task = client.SendAsync(request);

另一种尝试：

var client = new HttpClient();
client.DefaultRequestHeaders.Clear();
client.DefaultRequestHeaders.Connection.Add("keep-alive"); // Still results in "Keep-Alive"
string result = await client.GetStringAsync("http://www.someURI.com");

有一个关于如何在 HttpWebRequest 中完成它的答案：如何通过 HttpWebRequest 发送小写的 Keep-Alive 标头 https://stackoverflow.com/questions/9650236/how-to-send-lower-case-keep-alive-header-through-httpwebrequest

HttpClient 中可能有类似的事情吗？

你尝试过这个吗：

var client = new HttpClient();
client.DefaultRequestHeaders.Add("Connection", "keep-alive");

它给出了这个：