public string Validate(string captcha, string ipAddress) { if (string.IsNullOrEmpty(captcha)) { return("验证码为空。"); } try { JObject jObject; using (var response = HttpRequestHelper.CreatePostResponse( "https://www.recaptcha.net/recaptcha/api/siteverify", new Dictionary <string, string> { { "secret", _options.SecretKey }, { "response", captcha }, { "remoteip", ipAddress } })) { jObject = (JObject)HttpRequestHelper.GetObjectFromJsonResponse(response); } return(jObject.GetValue("success").Value <bool>() ? null : "人机验证时发生错误:" + string.Join(",", jObject["error-codes"].ToList())); } catch (Exception ex) { return("人机验证时发生错误:" + ex.Message); } }