C#实现网站登录

  public class HTMLHelper
    {
        /// <summary>   
        /// 获取CooKie  
        /// /// </summary>
        /// /// <param name="loginUrl"></param>   
        /// /// <param name="postdata"></param>   
        /// /// <param name="header"></param>  
        /// /// <returns></returns>      
        public static CookieContainer GetCooKie(string loginUrl, HttpHeader header)
        {
            HttpWebRequest request = null;
            HttpWebResponse response = null;
            try
            {
                CookieContainer cc = new CookieContainer();
                request = (HttpWebRequest)WebRequest.Create(loginUrl);
                request.Method = "GET";
                request.ContentType = header.contentType;
              
                 
                request.AllowAutoRedirect = false;
                request.CookieContainer = cc;
                request.KeepAlive = true;
                
                //接收响应        
                response = (HttpWebResponse)request.GetResponse();
                response.Cookies = request.CookieContainer.GetCookies(request.RequestUri);
                CookieCollection cook = response.Cookies;               //Cookie字符串格式    
                string strcrook = request.CookieContainer.GetCookieHeader(request.RequestUri);
                return cc;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

        /// <summary>   
        /// 获取CooKie  
        /// /// </summary>
        /// /// <param name="loginUrl"></param>   
        /// /// <param name="postdata"></param>   
        /// /// <param name="header"></param>  
        /// /// <returns></returns>      
        public static CookieContainer GetCooKie(string loginUrl, string postdata, HttpHeader header)
        {
            HttpWebRequest request = null;
            HttpWebResponse response = null;
            try
            {
                CookieContainer cc = new CookieContainer();
                request = (HttpWebRequest)WebRequest.Create(loginUrl);
                request.Method = header.method;
                request.ContentType = header.contentType;
                byte[] postdatabyte = Encoding.UTF8.GetBytes(postdata);
                request.ContentLength = postdatabyte.Length;
                request.AllowAutoRedirect = false;
                request.CookieContainer = cc;
                request.KeepAlive = true;
                //提交请求      
                Stream stream;
                stream = request.GetRequestStream();
                stream.Write(postdatabyte, 0, postdatabyte.Length);
                stream.Close();
                //接收响应        
                response = (HttpWebResponse)request.GetResponse();
                response.Cookies = request.CookieContainer.GetCookies(request.RequestUri);
                CookieCollection cook = response.Cookies;               //Cookie字符串格式    
                string strcrook = request.CookieContainer.GetCookieHeader(request.RequestUri);
                return cc;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        /// <summary>
        /// 获取html  
        /// </summary>  
        /// <param name="getUrl"></param>   
        /// <param name="cookieContainer"></param>  
        /// <param name="header"></param>    
        /// <returns></returns>    

        public static string GetHtml(string getUrl, CookieContainer cookieContainer, HttpHeader header)
        {
            Thread.Sleep(1000);
            HttpWebRequest httpWebRequest = null;
            HttpWebResponse httpWebResponse = null;
            try
            {
                httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(getUrl);
                httpWebRequest.CookieContainer = cookieContainer;
                httpWebRequest.ContentType = header.contentType;
                httpWebRequest.ServicePoint.ConnectionLimit = header.maxTry;
                httpWebRequest.Referer = getUrl;
                httpWebRequest.Accept = header.accept;
                httpWebRequest.UserAgent = header.userAgent;
                httpWebRequest.Method = "GET";
                httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
                Stream responseStream = httpWebResponse.GetResponseStream();
                StreamReader streamReader = new StreamReader(responseStream, Encoding.UTF8);
                string html = streamReader.ReadToEnd();
                streamReader.Close();
                responseStream.Close();
                httpWebRequest.Abort();
                httpWebResponse.Close();
                return html;
            }
            catch (Exception e)
            {
                if (httpWebRequest != null) httpWebRequest.Abort();
                if (httpWebResponse != null) httpWebResponse.Close();
                return string.Empty;
            }
        }

        /// <summary>
        /// 获取html  
        /// </summary>  
        /// <param name="getUrl"></param>   
        /// <param name="cookieContainer"></param>  
        /// <param name="header"></param>    
        /// <returns></returns>    

        public static string GetHtml(string getUrl,string post, CookieContainer cookieContainer, HttpHeader header,Encoding en)
        {
            Thread.Sleep(1000);
            HttpWebRequest myHttpWebRequest = null;
            HttpWebResponse httpWebResponse = null;
            try
            {               
                byte[] oneData = Encoding.Default.GetBytes(post);
                Uri uri = new Uri(getUrl);
                myHttpWebRequest = (HttpWebRequest)WebRequest.Create(uri);//请求的URL
                myHttpWebRequest.CookieContainer = cookieContainer;//*发送COOKIE
                myHttpWebRequest.Method = header.method;
                myHttpWebRequest.ContentType = header.contentType;
                myHttpWebRequest.ContentLength = oneData.Length;
                Stream newMyStream = myHttpWebRequest.GetRequestStream();
                newMyStream.Write(oneData, 0, oneData.Length);

                try
                {
                    httpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();
                    StreamReader sr = new StreamReader(httpWebResponse.GetResponseStream(), en);

                    string str = sr.ReadToEnd();

                    string msg = string.Empty;

                    return str;
                }
                catch (Exception ex)
                {
                    return string.Empty;
                }
            }
            catch (Exception e)
            {
                if (myHttpWebRequest != null) myHttpWebRequest.Abort();
                if (httpWebResponse != null) httpWebResponse.Close();
                return string.Empty;
            }
            return string.Empty;
        }

        /// <summary>
        /// 获取html  
        /// </summary>  
        /// <param name="getUrl"></param>   
        /// <param name="cookieContainer"></param>  
        /// <param name="header"></param>    
        /// <returns></returns>    

        public static string GetHtml(string getUrl, string post, CookieContainer cookieContainer,out CookieContainer co, HttpHeader header, Encoding en)
        {
            Thread.Sleep(1000);
            HttpWebRequest myHttpWebRequest = null;
            HttpWebResponse httpWebResponse = null;
            co = new CookieContainer();
            try
            {
                byte[] oneData = Encoding.Default.GetBytes(post);
                Uri uri = new Uri(getUrl);
                myHttpWebRequest = (HttpWebRequest)WebRequest.Create(uri);//请求的URL
                if (cookieContainer.Count > 0)
                {
                    myHttpWebRequest.CookieContainer = cookieContainer;
                }
                else
                {
                    myHttpWebRequest.CookieContainer = co;
                }
                
                myHttpWebRequest.Method = header.method;
                myHttpWebRequest.ContentType = header.contentType;
                myHttpWebRequest.ContentLength = oneData.Length;
                Stream newMyStream = myHttpWebRequest.GetRequestStream();
                newMyStream.Write(oneData, 0, oneData.Length);

                try
                {
                    httpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();
                    StreamReader sr = new StreamReader(httpWebResponse.GetResponseStream(), en);

                    httpWebResponse.Cookies = myHttpWebRequest.CookieContainer.GetCookies(myHttpWebRequest.RequestUri);
                    CookieCollection cook = httpWebResponse.Cookies;               //Cookie字符串格式    
                    string strcrook = myHttpWebRequest.CookieContainer.GetCookieHeader(myHttpWebRequest.RequestUri);

                    string str = sr.ReadToEnd();

                    string msg = string.Empty;

                    return str;
                }
                catch (Exception ex)
                {
                    return string.Empty;
                }
            }
            catch (Exception e)
            {
                if (myHttpWebRequest != null) myHttpWebRequest.Abort();
                if (httpWebResponse != null) httpWebResponse.Close();
                return string.Empty;
            }
            return string.Empty;
        }



        /// <summary>
        /// 获取Stream  
        /// </summary>  
        /// <param name="getUrl"></param>   
        /// <param name="cookieContainer"></param>  
        /// <param name="header"></param>    
        /// <returns></returns>    

        public static Stream GetStream(string getUrl, CookieContainer cookieContainer, HttpHeader header)
        {
            Thread.Sleep(1000);
            HttpWebRequest httpWebRequest = null;
            HttpWebResponse httpWebResponse = null;
            try
            {
                httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(getUrl);
                httpWebRequest.CookieContainer = cookieContainer;
                httpWebRequest.ContentType = header.contentType;
                httpWebRequest.ServicePoint.ConnectionLimit = header.maxTry;
                httpWebRequest.Referer = header.referer;
                httpWebRequest.Accept = header.accept;
                httpWebRequest.UserAgent = header.userAgent;
                httpWebRequest.Method = "GET";
                httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
                Stream responseStream = httpWebResponse.GetResponseStream();

                return responseStream;
            }
            catch (Exception e)
            {
                if (httpWebRequest != null) httpWebRequest.Abort();
                if (httpWebResponse != null) httpWebResponse.Close();
                return null;
            }
        }
     
        public static Stream GetStream(string getUrl, CookieContainer cookieContainer, out CookieContainer co, HttpHeader header)
        {

            Thread.Sleep(1000);
            HttpWebRequest httpWebRequest = null;
            HttpWebResponse httpWebResponse = null;
            co = new CookieContainer();
            try
            {
                httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(getUrl);
                if (cookieContainer.Count > 0)
                {
                    httpWebRequest.CookieContainer = cookieContainer;
                }
                else
                {
                    httpWebRequest.CookieContainer = co;
                }
               
                httpWebRequest.ContentType = header.contentType;
                httpWebRequest.ServicePoint.ConnectionLimit = header.maxTry;
                httpWebRequest.Referer = getUrl;
                httpWebRequest.Accept = header.accept;
                httpWebRequest.UserAgent = header.userAgent;
                httpWebRequest.Method = "GET";
                httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
                Stream responseStream = httpWebResponse.GetResponseStream();



                httpWebResponse.Cookies = httpWebRequest.CookieContainer.GetCookies(httpWebRequest.RequestUri);
                CookieCollection cook = httpWebResponse.Cookies;               //Cookie字符串格式    
                string strcrook = httpWebRequest.CookieContainer.GetCookieHeader(httpWebRequest.RequestUri);
                

                return responseStream;
            }
            catch (Exception e)
            {
                if (httpWebRequest != null) httpWebRequest.Abort();
                if (httpWebResponse != null) httpWebResponse.Close();
                return null;
            }
        }

    }



    public class HttpHeader
    {
        public string contentType { get; set; }
        public string accept { get; set; }
        public string userAgent { get; set; }
        public string method { get; set; }
        public int maxTry { get; set; }
        public string referer { get; set; }
    }