c# HttpWebResponse 调用WebApi

public static class WebApiCaller
    {
        public static string HttpPost(string url, string body)
        {
            try
            {
                //ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
                Encoding encoding = Encoding.UTF8;
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
                request.Method = "POST";
                request.Accept = "application/json, text/javascript, */*"; //"text/html, application/xhtml+xml, */*";
                request.ContentType = "application/json; charset=utf-8";

                byte[] buffer = encoding.GetBytes(body);
                request.ContentLength = buffer.Length;
                request.GetRequestStream().Write(buffer, 0, buffer.Length);
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                using (StreamReader reader = new StreamReader(response.GetResponseStream(), encoding))
                {
                    return reader.ReadToEnd();
                }
            }
            catch (WebException ex)
            {
                var res = (HttpWebResponse)ex.Response;
                StringBuilder sb = new StringBuilder();
                StreamReader sr = new StreamReader(res.GetResponseStream(), Encoding.UTF8);
                sb.Append(sr.ReadToEnd());
                //string ssb = sb.ToString();
                throw new Exception(sb.ToString());
            }
        }

        /// <summary>  
        /// GET Method  
        /// </summary>  
        /// <returns></returns>  
        public static string HttpGet(string url)
        {
            HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(url);
            myRequest.Method = "GET";

            HttpWebResponse myResponse = null;
            try
            {
                myResponse = (HttpWebResponse)myRequest.GetResponse();
                StreamReader reader = new StreamReader(myResponse.GetResponseStream(), Encoding.UTF8);
                string content = reader.ReadToEnd();
                return content;
            }
            //异常请求  
            catch (WebException e)
            {
                myResponse = (HttpWebResponse)e.Response;
                using (Stream errData = myResponse.GetResponseStream())
                {
                    using (StreamReader reader = new StreamReader(errData))
                    {
                        string text = reader.ReadToEnd();

                        return text;
                    }
                }
            }
        }
    }

string result = WebApiCaller.HttpPost("http://localhost:8082/api/Patient/SavePatient", jsonString);
string result1 = WebApiCaller.HttpGet("http://localhost:8080/api/Patient/GetPatientInfoById?Id=55");