C# 请求API（一次登陆，多次请求）

// User Session & cookie
    public class APISession
    {
        private string cookie;

        public string Cookie
        {
            get {  return cookie; }

            set {  cookie = value;}
        }

        private string session;

        public string Session
        {
            get {  return session;}

            set {  session = value;}
        }

        private DateTime expiretime;

        public DateTime Expiretime
        {
            get {  return expiretime;}

            set {  expiretime = value;}
        }

        private string url = System.Configuration.ConfigurationSettings.AppSettings["QCServer"]; // domain url

        public string Url
        {
            get { return url;}

            set { url = value;}
        }            
    }

//请求对象 
public class Requester
    {
        private string username;

        public string Username
        {
            get { return username; }
            set { username = value; }
        }
        private string password;

        public string Password
        {
            get { return password; }
            set { password = value; }
        }
        bool isauthforQC = false;

        public bool IsauthforQC
        {
            get { return isauthforQC; }
            set { isauthforQC = value; }
        }
        private APISession qs = new APISession();

        public APISession Qs
        {
            get { return qs; }
            set { qs = value; }
        }

        private Connection _instance;

        public Connection Instance
        {
            get { return _instance; }
            set { _instance = value; }
        }

    }

  public class Connection
    {
        //实例化Connection对象
        public static Connection GetInstance(Requester reqer)
        {
            Connection instance = null;
            if (!reqer.IsauthforQC)
            {
                instance = new Connection();
                reqer.Instance = instance;
            }
            else
            {
                instance = reqer.Instance;
            }
            return instance;
        }

        /// <summary>
        /// 通过初始化，进行登陆授权并保存Cookie 和Session到请求对象中，下次使用
        /// </summary>
        /// <param name="reqer"></param>
        /// <returns></returns>
        public bool initConnection(Requester reqer)
        {
            string url = reqer.Qs.Url + @"/qcbin/authentication-point/authenticate";// 校验登陆成功，并返回Cookie 
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "Get";
            request.ContentType = "application/xml";

            string authInfo = reqer.Username.Trim() + ":" + reqer.Password.Trim();
            authInfo = Convert.ToBase64String(Encoding.Default.GetBytes(authInfo));
            request.Headers[HttpRequestHeader.Authorization] = "Basic " + authInfo;
            try
            {
                using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
                { 
                    string StrCookie = response.Headers.ToString();
                    string StrCookie1 = StrCookie.Substring(StrCookie.IndexOf("LWSSO_COOKIE_KEY=") + 17);// 截取Cookie 
                    StrCookie1 = StrCookie1.Substring(0, StrCookie1.IndexOf(";"));
                    reqer.Qs.Cookie = StrCookie1; // 保存Cookie 到requester 对象
                    StreamReader reader = new StreamReader(response.GetResponseStream());
                    string result = reader.ReadToEnd().ToString();
                    Uri target = new Uri(reqer.Qs.Url);
                    HttpWebRequest myWebRequest1 = (HttpWebRequest)WebRequest.Create(reqer.Qs.Url + @"/qcbin/rest/site-session");// 校验登陆成功，并返回Session
                    myWebRequest1.Method = "Post";
                    myWebRequest1.ContentType = "text/xml";
                    myWebRequest1.CookieContainer = new CookieContainer();
                    myWebRequest1.CookieContainer.Add(new Cookie("LWSSO_COOKIE_KEY", StrCookie1) {Domain = target.Host });// 添加Cookie 到本次请求
                    WebResponse webResponse1 = myWebRequest1.GetResponse();
                    string strCookie2 = webResponse1.Headers.ToString();
                    strCookie2 = strCookie2.Substring(strCookie2.IndexOf("QCSession=")+ 10);// 截取Session
                    strCookie2 = strCookie2.Substring(0, strCookie2.IndexOf(";"));
                    reqer.Qs.Session = strCookie2;// 保存Session到requester 对象
                    reqer.Qs.Expiretime = DateTime.Now.AddMinutes(2);//设定请求有效期
                }
            }
            catch (Exception e)
            {
                                
                return false;
            }
            reqer.IsauthforQC = true;// 授权成功 
            return true;

        }
        /// <summary>
        /// 通过Get 请求获取API信息
        /// </summary>
        /// <param name="reqer">请求对象</param>
        /// <param name="queryURL">请求具体API方法</param>
        /// <param name="requesttype">请求类型（GET，Post..）</param>
        /// <param name="accepttype">接受类型（application/json..）</param>
        /// <returns></returns>
        public string SendRequest(Requester reqer, string queryURL, string requesttype, string accepttype)
        {
            bool isauth = false;
            string result = string.Empty;

            if (!reqer.IsauthforQC)
            {
                isauth = initConnection(reqer);
            }
            else
            {
                isauth = true;
            }

            if (isauth)
            {
                HttpWebRequest myWebRequest2 = (HttpWebRequest)WebRequest.Create(reqer.Qs.Url + queryURL);
                myWebRequest2.Method = requesttype;
                myWebRequest2.ContentType = "application/json";
                myWebRequest2.Accept = accepttype;
                myWebRequest2.CookieContainer = new CookieContainer();
                Uri target = new Uri(reqer.Qs.Url);
                myWebRequest2.CookieContainer.Add(new Cookie("LWSSO_COOKIE_KEY", reqer.Qs.Cookie) { Domain = target.Host });// 添加Cookie 到本次请求
                myWebRequest2.CookieContainer.Add(new Cookie("QCSession", reqer.Qs.Session) { Domain = target.Host });// 添加Session 到本次请求
                try
                {
                    WebResponse webResponse2 = myWebRequest2.GetResponse();
                    StreamReader reader2 = new StreamReader(webResponse2.GetResponseStream());
                    result = reader2.ReadToEnd().ToString();//获取结果
                }
                catch (Exception e)
                {

                    result = "";
                }
            }
            return result;
        }
        /// <summary>
        /// 通过PUT请求修改对象信息
        /// </summary>
        /// <param name="reqer"></param>
        /// <param name="updateValue"></param>
        /// <param name="requesttype"></param>
        /// <param name="accepttype"></param>
        /// <param name="domain"></param>
        /// <returns></returns>
        public string PUTRequest(Requester reqer, string updateValue, string requesttype, string accepttype, string domain)
        {
            bool isauth = false;
            string result = "";
            int columnsize = 385;     // the field column is varchar(255) in DB
            if (!reqer.IsauthforQC)
            {
                isauth = initConnection(reqer);
            }
            else
            {
                isauth = true;
            }
            if (isauth)
            {
                try
                {
                    HttpWebRequest myWebRequest2;
                 
                    // get the current value
                    string url = "URL";//需要访问的方法
                    var projectstr = SendRequest(reqer, url, "Get", "application/json");// 获取返回结果

                    JObject Fields = (JObject)JsonConvert.DeserializeObject(projectstr);
                    StringBuilder currentValue = new StringBuilder();
                    
                    // 获取需要修改对象属性值
                    JArray fld = (JArray)Fields["Fields"];
                    foreach (JObject item in fld)
                    {
                        if (item["Name"].ToString().Equals("user-template-13"))
                        {
                            try
                            {
                                // append the existing value
                                currentValue.Append(item["values"][0]["value"].ToString());
                            }
                            catch (Exception)
                            {
                            }
                        }
                    }
                    // append the new value
                    currentValue.Append(updateValue);//在原值后面增加新值
                     
                    myWebRequest2 = (HttpWebRequest)WebRequest.Create(reqer.Qs.Url + "url1");//访问更新的方法

                    myWebRequest2.Method = "PUT";
                    myWebRequest2.ContentType = "application/xml";
                    myWebRequest2.Accept = "application/xml";
                    myWebRequest2.CookieContainer = new CookieContainer();
                    Uri target = new Uri(reqer.Qs.Url);
                    myWebRequest2.CookieContainer.Add(new Cookie("LWSSO_COOKIE_KEY", reqer.Qs.Cookie) { Domain = target.Host });
                    myWebRequest2.CookieContainer.Add(new Cookie("QCSession", reqer.Qs.Session) { Domain = target.Host });

                    // xml 对象
                    XDocument postDoc = new XDocument(
                            new XElement("Entity", new XAttribute("Type", "test"),
                            new XElement("Fields",
                            new XElement("Field", new XAttribute("Name", "user-template-13"), new XElement("Value", currentValue.ToString())))));
                    // xml 对象

                    var bytes = Encoding.ASCII.GetBytes(postDoc.ToString());
                    Stream requestStream = myWebRequest2.GetRequestStream();

                    // the field column is varchar(255) in DB
                    if (bytes.Length > columnsize)
                    {
                        return "Limit";
                    }
                    requestStream.Write(bytes, 0, bytes.Length);
                    requestStream.Close();

                    HttpWebResponse res = (HttpWebResponse)myWebRequest2.GetResponse();
                    if (res.StatusCode == HttpStatusCode.OK)
                    {
                        result = "Success";
                    }
                    else
                    {
                        result = "Fail";
                    }
                } 
                catch (WebException ex)
                {
                    result = "Fail";
                    throw ex;
                }
                catch (Exception ex)
                {
                    result = "Fail";
                    throw ex;
                }
            }
            return result;
        }
    }