API: https://api.linkedin.com/v2/me?projection=(id,firstName,lastName)
Разрешение приложения: r_basicprofile, r_emailaddress, w_share
ServicePointManager.Expect100Continue = true;
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
string requesturl = "https://api.linkedin.com/v2/me?projection=(id,firstName,lastName)";
HttpWebRequest webRequest = System.Net.WebRequest.Create(requesturl) as HttpWebRequest;
webRequest.Method = "GET";
webRequest.Host = "api.linkedin.com";
//webRequest.ContentType = "application/x-www-form-urlencoded";
//webRequest.Connection = "Keep-Alive";
webRequest.Headers.Add("Authorization", "Bearer " + accessToken);
//Stream dataStream = webRequest.GetRequestStream();
//String postData = String.Empty;
//byte[] postArray = Encoding.ASCII.GetBytes(postData);
//dataStream.Write(postArray, 0, postArray.Length);
//dataStream.Close();
WebResponse response = webRequest.GetResponse();
Stream dataStream = response.GetResponseStream();
StreamReader responseReader = new StreamReader(dataStream);
String returnVal = responseReader.ReadToEnd().ToString();