C# 中的 cURL 和用户身份验证

我想在 C# 中执行以下 cURL 请求：

curl -u admin:geoserver -v -XPOST -H 'Content-type: text/xml' \
   -d '<workspace><name>acme</name></workspace>' \
   http://localhost:8080/geoserver/rest/workspaces

我尝试过使用 WebRequest：

string url = "http://localhost:8080/geoserver/rest/workspaces";
WebRequest request = WebRequest.Create(url);

request.ContentType = "Content-type: text/xml";
request.Method = "POST";
request.Credentials = new NetworkCredential("admin", "geoserver");

byte[] buffer = Encoding.GetEncoding("UTF-8").GetBytes("<workspace><name>my_workspace</name></workspace>");
Stream reqstr = request.GetRequestStream();
reqstr.Write(buffer, 0, buffer.Length);
reqstr.Close();

WebResponse response = request.GetResponse();
...

但我收到错误：(400) 错误请求。

如果我更改请求凭据并在标头中添加身份验证：

string url = "http://localhost:8080/geoserver/rest/workspaces";
WebRequest request = WebRequest.Create(url);

request.ContentType = "Content-type: text/xml";
request.Method = "POST";
string authInfo = "admin:geoserver";
request.Headers["Authorization"] = "Basic " + authInfo;

byte[] buffer = Encoding.GetEncoding("UTF-8").GetBytes("<workspace><name>my_workspace</name></workspace>");
Stream reqstr = request.GetRequestStream();
reqstr.Write(buffer, 0, buffer.Length);
reqstr.Close();

WebResponse response = request.GetResponse();
...

然后我得到：（401）未经授权。

我的问题是：我应该使用其他 C# 类（例如 WebClient 或 HttpWebRequest）还是必须使用 .NET 的curl 绑定？

所有意见或指导将不胜感激。

HTTP 基本身份验证需要以下所有内容"Basic "要进行 Base64 编码，所以尝试

request.Headers["Authorization"] = "Basic " + 
    Convert.ToBase64String(Encoding.ASCII.GetBytes(authInfo));