关于C# 怎么调用webapi来获取到json数据

        /// <summary>
        /// 调用api返回json
        /// </summary>
        /// <param name="url">api地址</param>
        /// <param name="jsonstr">接收参数</param>
        /// <param name="type">类型</param>
        /// <returns></returns>
        public static string HttpApi(string url, string jsonstr, string type)
        {
            Encoding encoding = Encoding.UTF8;
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);//webrequest请求api地址
            request.Accept = "text/html,application/xhtml+xml,*/*";
            request.ContentType = "application/json";
            request.Method = type.ToUpper().ToString();//get或者post
            byte[] buffer = encoding.GetBytes(jsonstr);
            request.ContentLength = buffer.Length;
            request.GetRequestStream().Write(buffer, , buffer.Length);
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
            {
                return reader.ReadToEnd();
            }
        }