I was able to do it my own using following code..
private void button2_Click(object sender, EventArgs e)
{
HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create("https://accounts.google.com/o/oauth2/token");
webRequest.ContentType = "application/x-www-form-urlencoded";
webRequest.Method = "POST";
authLink.AppendFormat("code={0}", code);
authLink.AppendFormat("&client_id={0}", "996688211762.apps.googleusercontent.com");
authLink.AppendFormat("&client_secret={0}", "nprfJuBUOyU2hsb3tqt1XDnB");
authLink.AppendFormat("&redirect_uri={0}", "urn:ietf:wg:oauth:2.0:oob");
authLink.Append("&grant_type=authorization_code");
UTF8Encoding utfenc = new UTF8Encoding();
byte[] bytes = utfenc.GetBytes(authLink.ToString());
Stream os = null;
try // send the post
{
webRequest.ContentLength = bytes.Length; // Count bytes to send
os = webRequest.GetRequestStream();
os.Write(bytes, 0, bytes.Length); // Send it
}
catch (Exception ex) { MessageBox.Show(ex.Message); }
try // get the response
{
HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse();
if (webResponse == null) { MessageBox.Show("null"); }
StreamReader sr = new StreamReader(webResponse.GetResponseStream());
textBox1.Text = sr.ReadToEnd().Trim();
//MessageBox.Show(sr.ReadToEnd().Trim());
}
catch (Exception ex) { MessageBox.Show(ex.Message); }
}
private void button1_Click(object sender, EventArgs e)
{
StringBuilder authLink = new StringBuilder();
authLink.Append("https://accounts.google.com/o/oauth2/auth");
authLink.AppendFormat("?scope={0}", "https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.email+https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.profile");
authLink.AppendFormat("&client_id={0}", "xxxxxx.apps.googleusercontent.com");
authLink.AppendFormat("&redirect_uri={0}", "urn:ietf:wg:oauth:2.0:oob");
authLink.Append("&response_type=code");
string u = @"https://accounts.google.com/o/oauth2/auth?scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.email+https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.profile&redirect_uri=urn:ietf:wg:oauth:2.0:oob&response_type=code&client_id=xxxxxxxx.apps.googleusercontent.com";
webBrowser1.Navigate(u);
}
I am assuming to have two button on window.. button1 is used to get CODE from google and button2 uses that code and get the access_token which is what I was looking for.