JSON与PostAPI

public class User
    {
        public string username { get; set; }
        public string password { get; set; }
    }

public class TestAPI
    {
        public int code { get; set; }
        public string message { get; set; }
        public string datetime { get; set; }
    }

    public static class HttpPost
    {
        /// 

        /// 带超时的Post发送Json，实现超时重发，启用接口日志
        /// 
        /// 地址
        /// Json字符串
        /// 编码类型
        /// 超时时间
        /// 
        public static string PostJson(string url, string data, Encoding encoding, int timeout)
        {
            try
            {
                //初始化配置
                HttpWebRequest tmpRequest = (HttpWebRequest)WebRequest.Create(url);
                tmpRequest.Method = "POST";
                tmpRequest.KeepAlive = false;
                tmpRequest.Timeout = timeout;
                tmpRequest.ContentType = "application/json";
                byte[] tmpBts = encoding.GetBytes(data);
                tmpRequest.ContentLength = tmpBts.Length;
                //提交数据
                Stream tmpRequestStream = tmpRequest.GetRequestStream();
                tmpRequestStream.Write(tmpBts, 0, tmpBts.Length);
                tmpRequestStream.Flush();
                //接收数据  
                HttpWebResponse tmpResponse = (HttpWebResponse)tmpRequest.GetResponse();
                Stream tmpResponseStream = tmpResponse.GetResponseStream();
                StreamReader tmpStreamReader = new StreamReader(tmpResponseStream, encoding);
                string retString = tmpStreamReader.ReadToEnd();
                //关闭
                tmpStreamReader.Close();
                tmpResponseStream.Close();
                tmpRequestStream.Close();
                //返回数据
                return retString;
            }
            catch (Exception ex)
            {
                return ex.ToString();
            }
        }
    }

using Newtonsoft.Json;
using System.Text;
using TestJsonAndWebAPI;

User user = new User()
{
    username = "test",
    password = "123456"
};
string tmpUserStr = JsonConvert.SerializeObject(user);
Console.WriteLine(tmpUserStr);

string url = "http://114.132.240.163:9999/ActionApi/TestAPI/Login";
string postDataStr = tmpUserStr;
Encoding encoding = Encoding.UTF8;
int TimeOut = 5000;
string testStr = HttpPost.PostJson(url, postDataStr, encoding, TimeOut);
TestAPI test = JsonConvert.DeserializeObject(testStr);
testStr = JsonConvert.SerializeObject(test);
Console.WriteLine(testStr);

完成