问使用c#建立与microsoft exchange service的连接

EN

static void Main(string[] args)
        {
            ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2013_SP1);

            service.Credentials = new WebCredentials("Student SA", "Pass1234");

            service.TraceEnabled = true;
            service.TraceFlags = TraceFlags.All;

            service.AutodiscoverUrl("students@student.edu", RedirectionUrlValidationCallback);

            // service.ImpersonatedUserId = new ImpersonatedUserId(ConnectingIdType.PrincipalName, "myADAccount");    

        }

        private static bool RedirectionUrlValidationCallback(string redirectionUrl)
        {
            // The default for the validation callback is to reject the URL.
            bool result = false;

            Uri redirectionUri = new Uri(redirectionUrl);

            // Validate the contents of the redirection URL. In this simple validation
            // callback, the redirection URL is considered valid if it is using HTTPS
            // to encrypt the authentication credentials. 
            if (redirectionUri.Scheme == "https")
            {
                result = true;
            }
            return result;
        }

    <Trace Tag="AutodiscoverConfiguration" Tid="9" Time="2018-06-04 15:10:07Z">  
 Request error: The remote server returned an error: (401) Unauthorized.  
 </Trace>