这样获取cookie和保持session的错在哪里？
CookieContainer cookieHeader = new CookieContainer();string postData = "loginName=abc&password=1234";
string loginUrl = "http://login.aaaa.com";
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
HttpWebRequest webRequest2 = (HttpWebRequest)WebRequest.Create(loginUrl);
webRequest2.CookieContainer = cookieHeader;
webRequest2.Method = "POST";
webRequest2.ContentType = "application/x-www-form-urlencoded";
webRequest2.ContentLength = byteArray.Length;
Stream newStream = webRequest2.GetRequestStream();
newStream.Write(byteArray, 0, byteArray.Length);
newStream.Close();
HttpWebResponse response2 = (HttpWebResponse)webRequest2.GetResponse();
cookieHeader = webRequest2.CookieContainer;string strPageUrl = "http://geturl.htm";
HttpWebRequest Myrequest = (HttpWebRequest)WebRequest.Create(strPageUrl);
Myrequest.CookieContainer = cookieHeader;
HttpWebResponse Myresponse = (HttpWebResponse)Myrequest.GetResponse();
Stream Mystream = Myresponse.GetResponseStream();
string sHtml = new StreamReader(Mystream, System.Text.Encoding.Default).ReadToEnd();
CookieContainer cookieHeader = new CookieContainer();string postData = "loginName=abc&password=1234";
string loginUrl = "http://login.aaaa.com";
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
HttpWebRequest webRequest2 = (HttpWebRequest)WebRequest.Create(loginUrl);
webRequest2.CookieContainer = cookieHeader;
webRequest2.Method = "POST";
webRequest2.ContentType = "application/x-www-form-urlencoded";
webRequest2.ContentLength = byteArray.Length;
Stream newStream = webRequest2.GetRequestStream();
newStream.Write(byteArray, 0, byteArray.Length);
newStream.Close();
HttpWebResponse response2 = (HttpWebResponse)webRequest2.GetResponse();
cookieHeader = webRequest2.CookieContainer;string strPageUrl = "http://geturl.htm";
HttpWebRequest Myrequest = (HttpWebRequest)WebRequest.Create(strPageUrl);
Myrequest.CookieContainer = cookieHeader;
HttpWebResponse Myresponse = (HttpWebResponse)Myrequest.GetResponse();
Stream Mystream = Myresponse.GetResponseStream();
string sHtml = new StreamReader(Mystream, System.Text.Encoding.Default).ReadToEnd();
下面是 HttpClient 类， 它继承自 WebClient，并重写了 GetWebRequest 方法。关键是要定义一个 Cookie 容器：
/// <summary>
/// 支持 Session 和 Cookie 的 WebClient。
/// </summary>
public class HttpClient : WebClient
{
// Cookie 容器
private CookieContainer cookieContainer; /**/
/// <summary>
/// 创建一个新的 WebClient 实例。
/// </summary>
public HttpClient()
{
this.cookieContainer = new CookieContainer();
} /**/
/// <summary>
/// 创建一个新的 WebClient 实例。
/// </summary>
/// <param name="cookie">Cookie 容器</param>
public HttpClient(CookieContainer cookies)
{
this.cookieContainer = cookies;
} /**/
/// <summary>
/// Cookie 容器
/// </summary>
public CookieContainer Cookies
{
get { return this.cookieContainer; }
set { this.cookieContainer = value; }
} /**/
/// <summary>
/// 返回带有 Cookie 的 HttpWebRequest。
/// </summary>
/// <param name="address"></param>
/// <returns></returns>
protected override WebRequest GetWebRequest(Uri address)
{
WebRequest request = base.GetWebRequest(address);
if (request is HttpWebRequest)
{
HttpWebRequest httpRequest = request as HttpWebRequest;
httpRequest.CookieContainer = cookieContainer;
}
return request;
} //封装了PostData, GetSrc 和 GetFile 方法#region 封装了PostData, GetSrc 和 GetFile 方法
/**/
/// <summary>
/// 向指定的 URL POST 数据，并返回页面
/// </summary>
/// <param name="uriString">POST URL</param>
/// <param name="postString">POST 的 数据</param>
/// <param name="postStringEncoding">POST 数据的 CharSet</param>
/// <param name="dataEncoding">页面的 CharSet</param>
/// <returns>页面的源文件</returns>
public string PostData(string uriString, string postString, string postStringEncoding, string dataEncoding, out string msg)
{
try
{
// 将 Post 字符串转换成字节数组
byte[] postData = Encoding.GetEncoding(postStringEncoding).GetBytes(postString);
this.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
// 上传数据，返回页面的字节数组
byte[] responseData = this.UploadData(uriString, "POST", postData);
// 将返回的将字节数组转换成字符串(HTML);
string srcString = Encoding.GetEncoding(dataEncoding).GetString(responseData);
srcString = srcString.Replace("\t", "");
srcString = srcString.Replace("\r", "");
srcString = srcString.Replace("\n", "");
msg = string.Empty;
return srcString;
}
catch (WebException we)
{
msg = we.Message;
return string.Empty;
}
} /**/
/// <summary>
/// 获得指定 URL 的源文件
/// </summary>
/// <param name="uriString">页面 URL</param>
/// <param name="dataEncoding">页面的 CharSet</param>
/// <returns>页面的源文件</returns>
public string GetSrc(string uriString, string dataEncoding, out string msg)
{
try
{
// 返回页面的字节数组
byte[] responseData = this.DownloadData(uriString);
// 将返回的将字节数组转换成字符串(HTML);
string srcString = Encoding.GetEncoding(dataEncoding).GetString(responseData);
srcString = srcString.Replace("\t", "");
srcString = srcString.Replace("\r", "");
srcString = srcString.Replace("\n", "");
msg = string.Empty;
return srcString;
}
catch (WebException we)
{
msg = we.Message;
return string.Empty;
}
} /**/
/// <summary>
/// 从指定的 URL 下载文件到本地
/// </summary>
/// <param name="uriString">文件 URL</param>
/// <param name="fileName">本地文件的完成路径</param>
/// <returns></returns>
public bool GetFile(string urlString, string fileName, out string msg)
{
try
{
this.DownloadFile(urlString, fileName);
msg = string.Empty;
return true;
}
catch (WebException we)
{
msg = we.Message;
return false;
}
}
}
示例： Code ：
string err = "";
string str = "";
HttpClient hc = new HttpClient();
str=hc.GetSrc("http://localhost:9316/login.aspx?id=A8558157-DE14-43E4-8B11-2D8D174DC28E", "utf-8", out err);
textBox1.Text = str;
https://www.google.com/#hl=en&cp=6&gs_id=5u&xhr=t&q=%E5%B1%B1%E9%87%8E%E7%A0%81%E5%A4%AB%E4%B9%8B-%E8%8E%B7%E5%8F%96HTML&tok=leWKKNFoK5eROsRnsnhsMw&pq=%E5%B1%B1%E9%87%8E%E7%A0%81%E5%A4%AB%E8%8E%B7%E5%8F%96html&pf=p&sclient=psy-ab&newwindow=1&biw=1440&bih=785&source=hp&pbx=1&oq=%E5%B1%B1%E9%87%8E%E7%A0%81%E5%A4%AB%E4%B9%8B-%E8%8E%B7%E5%8F%96HTML&aq=f&aqi=&aql=&gs_sm=&gs_upl=&bav=on.2,or.r_gc.r_pw.r_cp.,cf.osb&fp=228b63168821ee4b