private string Token = ConfigurationManager.AppSettings["Token"]; [HttpGet] [ActionName("Index")] public ActionResult Get(string signature, string timestamp, string nonce, string echostr) {  if (CheckSignature.Check(signature, timestamp, nonce, Token))  {  return Content(echostr);//返回隨機字符串則表示驗證通過  }  else  {  return Content("failed:" + signature + "," + CheckSignature.GetSignature(timestamp, nonce, Token) + "。如果你在瀏覽器中看到這句話，說明此地址可以被作為微信公眾賬號后臺的Url，請注意保持Token一致。");  } } /// <summary> /// 檢查簽名是否正確 /// </summary> /// <param name="signature"></param> /// <param name="timestamp"></param> /// <param name="nonce"></param> /// <param name="token"></param> /// <returns></returns> public static bool Check(string signature, string timestamp, string nonce, string token = null) {  return signature == GetSignature(timestamp, nonce, token); } /// <summary> /// 返回正確的簽名 /// </summary> /// <param name="timestamp"></param> /// <param name="nonce"></param> /// <param name="token"></param> /// <returns></returns> public static string GetSignature(string timestamp, string nonce, string token = null) {  token = token ?? Token;  var arr = new[] { token, timestamp, nonce }.OrderBy(z => z).ToArray();  var arrString = string.Join("", arr);  //var enText = FormsAuthentication.HashPasswordForStoringInConfigFile(arrString, "SHA1");//使用System.Web.Security程序集  var sha1 = System.Security.Cryptography.SHA1.Create();  var sha1Arr = sha1.ComputeHash(Encoding.UTF8.GetBytes(arrString));  StringBuilder enText = new StringBuilder();  foreach (var b in sha1Arr)  {  enText.AppendFormat("{0:x2}", b);  }  return enText.ToString(); }