net 6 用HttpClient发送XML PostAsync

/// <summary>
/// 发送Post请求
/// </summary>
public static String PostXml(String xml)
{
HttpClient hClient = new HttpClient();
//hClient.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "application/xml");
hClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/xml"));
var contentString = new StringContent(xml, Encoding.UTF8, "application/xml");
HttpResponseMessage response = hClient.PostAsync(URL, contentString).GetAwaiter().GetResult();
return response.Content.ReadAsStringAsync().GetAwaiter().GetResult();
}