title: How do I escape POST body correctly?
body: <p>I need to send some JSON values to the server using POST requests; sending them without any escaping works fine, but this is not a proper solution as these values might contain special symbols like ? and &amp;.<br>
  I've tried answers from another questions (Uri.EscapeDataString, Uri.EscapeUriString, System.Net.WebUtility.UrlEncode, System.Web.HttpUtility.UrlEncode) but they all make the server return a "Bad request" error.<br>
  How can I escape POST values <strong>properly</strong>?</p>