// Create the web request

HttpWebRequest request

　　= WebRequest.Create("https://outlook.office365.com/api/v1.0/me/messages/$count?$filter=IsRead%20eq%20false") as HttpWebRequest;

// Add authentication to request

request.Credentials = new NetworkCredential("username", "password");

// Get response

using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)

{

  // Get the response stream

    StreamReader reader = new StreamReader(response.GetResponseStream());

    // 显示在前台控件中

    unreadCount.Text = reader.ReadToEnd();

}