c#后台代码请求访问api接口

      前言：最近公司项目与外部api接口对接较多 ，写下自己的代码总结。介绍两种访问方式（HttpClient、HttpWebRequest）

一、HttpWebRequest 访问Api

 private static string webPost(string url, string obj = null)
        {
            string param = (obj);//参数
            byte[] bs = Encoding.Default.GetBytes(param);
            HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);
            req.Method = "POST";
            req.ContentType = "application/json";
            req.ContentLength = bs.Length;
            using (Stream reqStream = req.GetRequestStream())
            {
                reqStream.Write(bs, 0, bs.Length);
                reqStream.Close();
                HttpWebResponse response2 = (HttpWebResponse)req.GetResponse();
                StreamReader sr2 = new StreamReader(response2.GetResponseStream(), Encoding.UTF8);
                string result = sr2.ReadToEnd();
                return result;
            }
        }

二、HttpClient访问Api

 /// <summary>
/// Get请求
/// </summary>

public string GetToken()

{

            try
            {
                HttpClient myHttpClient = new HttpClient();
                var urlstring = "https://oapi.dingtalk.com/gettoken?appkey=APPKEY&appsecret=APPSECRET";
                urlstring = urlstring.Replace("APPKEY", appkey);
                urlstring = urlstring.Replace("APPSECRET", appsecret);
                HttpResponseMessage response = myHttpClient.GetAsync(urlstring).Result;
                var content = response.Content.ReadAsAsync<object>().Result;
                return content；
            }
            catch (Exception ex)
            {
                return ex.Message；
            }
}

/// <summary>
/// Post请求
/// </summary>
 public string getList(long unixstart, long unixend, int cursor, bool start) {
            try
            {
                HttpClient myHttpClient = new HttpClient();
                var urlstring = "https://oapi.dingtalk.com/topapi/processinstance/listids?access_token=ACCESS_TOKEN";
                urlstring = urlstring.Replace("ACCESS_TOKEN", access_token);
                var content = new FormUrlEncodedContent(new Dictionary<string, string>() {
                      {"process_code",""},
                      {"start_time", },
                      {"end_time" ,},
                      {"size" ,"10"},
                      {"cursor" ,)}
                  });
                HttpResponseMessage response = myHttpClient.PostAsync(urlstring, content).Result;
                var jsonlist = response.Content.ReadAsAsync<object>().Result;
               return jsonlist;
            }
            catch (Exception ex)
            {
                   return e.Message; 
            }
 }

三、时间戳与DateTime互转

 /// <summary>
        /// 将c# DateTime时间格式转换为Unix时间戳格式
        /// </summary>
        /// <param name="time"></param>
        /// <returns></returns>
        public  long ConvertDateTimeInt(DateTime time)
        {
            DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1, 0, 0, 0, 0));
            long t = (time.Ticks - startTime.Ticks) / 10000;
            return t;
        }

        /// <summary>
        /// c# Unix时间戳格式转换成DateTime
        /// </summary>
        /// <param name="d"></param>
        /// <returns></returns>
        public  System.DateTime ConvertIntDateTime(long d)
        {
            System.DateTime time = System.DateTime.MinValue;
            System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1));
            time = startTime.AddMilliseconds(d);
            return time;
        }