从外部API读取JSON响应中返回的错误对象

Question

我正在使用.net webservice通过JSON与外部API（Urban Airship）进行通信。在我的出站JSON中有一些不正确的东西，据说，随着我看到的400 Bad Request错误，他们正在向我返回一个JSON对象，它有错误记录，可以帮助我识别问题。

唯一的问题是，我无法弄清楚如何接受和阅读JSON错误消息......我得到的只是400 Bad Request。有没有办法可以修改我的代码来查看这个返回的对象？

HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(uri);

req.ContentType = contentType;
req.Method = method;
req.ContentLength = jsonDataBytes.Length;

CredentialCache credentialCache = new CredentialCache();
string username = "x";
string password = y
credentialCache.Add(uri, "Basic", new NetworkCredential(username, password));

req.Credentials = credentialCache;

req.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(new ASCIIEncoding().GetBytes(username + ":" + password)));
req.Accept = "application/vnd.urbanairship+json; version=3;";

dynamic stream = req.GetRequestStream();
stream.Write(jsonDataBytes, 0, jsonDataBytes.Length);
stream.Close();

dynamic response = req.GetResponse().GetResponseStream();
StreamReader reader = new StreamReader(response);
dynamic res = reader.ReadToEnd();
reader.Close();
response.Close();