c# - 使用 c# http 客户端时，请求 header 必须仅包含 ASCII 字符吗？

Question

我正在使用 HttpClient通过传递 header 进行 POST 调用，但在某个时间点我收到如下错误:

Request headers must contain only ASCII characters.

使用堆栈跟踪:

at System.Net.Http.HttpConnection.WriteStringAsync(String s)
   at System.Net.Http.HttpConnection.WriteHeadersAsync(HttpHeaders headers, String cookiesFromContainer)
   at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithNtConnectionAuthAsync(HttpConnection connection, HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.DiagnosticsHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.HttpClient.FinishSendAsyncBuffered(Task`1 sendTask, HttpRequestMessage request, CancellationTokenSource cts, Boolean disposeCts)

这是我的代码:

public HttpWrapper(string endpoint, Func<IDictionary<string, string>> NewHeader)
{
    _httpClient = new HttpClient();
    _httpClient.BaseAddress = new Uri(endpoint);

    if (NewHeader != null)
    {
        var headers = NewHeader();
        foreach (var header in headers)
        {
            _httpClient.DefaultRequestHeaders.TryAddWithoutValidation(header.Key, header.Value);
        }
    }
}

我需要对 header.Value 做些什么吗？解决这个问题？我在网上阅读，所以看起来我需要在这里使用 Utf-8，但不确定如何正确使用？
更新
我今天得到了这样的 header 值，并且自 HttpUtility.HtmlEncode 以来它抛出了相同的异常没有做任何事情。另外我不确定这个字符是什么 <0x94> ?任何想法为什么会发生？
我也不确定

Answer 1

您可以尝试将 header 值编码为 HTML:

_httpClient.DefaultRequestHeaders.TryAddWithoutValidation(header.Key, HttpUtility.HtmlEncode(header.Value));

您的字符串 Ergänzendes 将是“ Ergänzendes”。