public string GetToken()
{
if (!_authenticationToken.HasToken() || _authenticationToken.HasExpired())
{
string url = _marketoInstanceUrl + "identity/oauth/token?grant_type=client_credentials&client_id=" + _marketoClientId + "&client_secret=" + _marketoClientSecret;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.ContentType = "application/json";
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream resStream = response.GetResponseStream();
StreamReader reader = new StreamReader(resStream);
string json = reader.ReadToEnd();
AuthenticationTokenResponse authenticationTokenResponse = JsonConvert.DeserializeObject <AuthenticationTokenResponse>(json);
_authenticationToken = new AuthenticationToken()
{
AccessToken = authenticationTokenResponse.Access_token,
Expires = DateTime.Now.AddSeconds(authenticationTokenResponse.Expires_in - 500)
};
}
return(_authenticationToken.AccessToken);
}