好了，还是由于工作需要 要登录一个网站并且模拟点击下载某些东西
原理就是先对一个地址（地址是用户名和密码输入框所在的form的action对应的页面）进行POST提交用户名和密码（不考虑验证码，当然验证码也可以破解），用一个CookieContainer保持Response的cookie，保证了每次请求使用同一个已经登录的session。
本类部分代码来源于网上，功能有待完善，目前只实现了登录和登录后访问“后台”页面。
代码：
public class LogingHelper
{
public static CookieContainer theCC = new CookieContainer();
/// <summary>
/// 登录方法(无验证码)
/// </summary>
/// <param name="url">POST请求的地址
/// <param name="paramList">参数列表 例如 name=zhangsan&pass=lisi
/// <param name="referer">来源地址
/// <returns></returns>
public static string Login(String url, String paramList, string referer)
{
HttpWebResponse res = null;
HttpWebRequest req = null;
string strResult = "";
try
{
req = (HttpWebRequest)WebRequest.Create(url);
//配置请求header
req.Headers.Add(HttpRequestHeader.AcceptCharset, "GBK,utf-8;q=0.7,*;q=0.3");
req.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip,deflate,sdch");
req.Headers.Add(HttpRequestHeader.AcceptLanguage, "zh-CN,zh;q=0.8");
req.Accept = "application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5";
req.KeepAlive = true;
req.Referer = referer;
req.Headers.Add(HttpRequestHeader.CacheControl, "max-age=0");
req.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US) AppleWebKit/534.7 (KHTML, like Gecko) Chrome/7.0.517.5 Safari/534.7";
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
req.AllowAutoRedirect = true;
//设置cookieContainer用来接收cookie
req.CookieContainer = theCC;
StringBuilder UrlEncoded = new StringBuilder();
//对参数进行encode
Char[] reserved = { '?', '=', '&' };
byte[] SomeBytes = null;
if (paramList != null)
{
int i = , j;
while (i < paramList.Length)
{
j = paramList.IndexOfAny(reserved, i);
if (j == -)
{
UrlEncoded.Append(HttpUtility.UrlEncode(paramList.Substring(i, paramList.Length - i)));
break;
}
UrlEncoded.Append(HttpUtility.UrlEncode(paramList.Substring(i, j - i)));
UrlEncoded.Append(paramList.Substring(j, ));
i = j + ;
}
SomeBytes = Encoding.UTF8.GetBytes(UrlEncoded.ToString());
req.ContentLength = SomeBytes.Length;
Stream newStream = req.GetRequestStream();
newStream.Write(SomeBytes, , SomeBytes.Length);
newStream.Close();
}
else
{
req.ContentLength = ;
}
//返回请求
res = (HttpWebResponse)req.GetResponse();
Encoding encode = System.Text.Encoding.GetEncoding("utf-8");
Stream responseStream = null;
if (res.ContentEncoding.ToLower() == "gzip")
{
responseStream = new System.IO.Compression.GZipStream(res.GetResponseStream(), System.IO.Compression.CompressionMode.Decompress);
}
else if (res.ContentEncoding.ToLower() == "deflate")
{
responseStream = new System.IO.Compression.DeflateStream(res.GetResponseStream(), System.IO.Compression.CompressionMode.Decompress);
}
else
{
responseStream = res.GetResponseStream();
}
StreamReader sr = new StreamReader(responseStream, encode);
strResult = sr.ReadToEnd();
}
catch (Exception e)
{
//writeLog
}
finally
{
res.Close();
}
return strResult;
}
/// <summary> 获取页面HTML
///
/// <param name="url">
/// <param name="paramList">
/// <returns></returns>
public static string getPage(String url, string referer)
{
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
string strResult = string.Empty;
req.Headers["If-None-Match"] = "36d0ed736e88c71:d9f";
req.Referer = referer;
req.CookieContainer = theCC;
HttpWebResponse res = (HttpWebResponse)req.GetResponse();
StreamReader sr = null;
try
{
sr = new StreamReader(res.GetResponseStream(), Encoding.UTF8);
strResult = sr.ReadToEnd();
}
catch (System.Exception ex)
{
//writeLog
}
finally
{
sr.Close();
}
return strResult;
} /// <summary>
/// 模仿异步请求POST的方法
/// </summary>
/// <param name="url">
/// <param name="referer">
/// <param name="methed">
/// <param name="paramList">
/// <returns></returns>
public static string VisitPage(string url, string referer, string paramList)
{
HttpWebResponse response = null;
string strResult = string.Empty;
try
{
HttpWebRequest request = HttpWebRequest.Create(url) as HttpWebRequest;
request.Method = "POST";
request.KeepAlive = true;
request.Referer = referer;
request.Headers.Add(HttpRequestHeader.AcceptCharset, "GBK,utf-8;q=0.7,*;q=0.3");
request.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip,deflate,sdch");
request.Headers.Add(HttpRequestHeader.AcceptLanguage, "zh-CN,zh;q=0.8");
request.Accept = "application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5";
request.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US) AppleWebKit/534.7 (KHTML, like Gecko) Chrome/7.0.517.5 Safari/534.7";
request.ContentType = "application/x-www-form-urlencoded";
request.CookieContainer = theCC;
request.Headers.Add("X-Requested-With", "XMLHttpRequest");
StringBuilder UrlEncoded = new StringBuilder();
//对参数进行encode
Char[] reserved = { '?', '=', '&' };
byte[] SomeBytes = null;
if (paramList != null)
{
int i = , j;
while (i < paramList.Length)
{
j = paramList.IndexOfAny(reserved, i);
if (j == -)
{
UrlEncoded.Append(HttpUtility.UrlEncode(paramList.Substring(i, paramList.Length - i)));
break;
}
UrlEncoded.Append(HttpUtility.UrlEncode(paramList.Substring(i, j - i)));
UrlEncoded.Append(paramList.Substring(j, ));
i = j + ;
}
SomeBytes = Encoding.UTF8.GetBytes(UrlEncoded.ToString());
request.ContentLength = SomeBytes.Length;
Stream newStream = request.GetRequestStream();
newStream.Write(SomeBytes, , SomeBytes.Length);
newStream.Close();
}
response = (HttpWebResponse)request.GetResponse();
Encoding encode = System.Text.Encoding.GetEncoding("utf-8");
Stream responseStream = null;
if (response.ContentEncoding.ToLower() == "gzip")
{
responseStream = new System.IO.Compression.GZipStream(response.GetResponseStream(), System.IO.Compression.CompressionMode.Decompress);
}
else if (response.ContentEncoding.ToLower() == "deflate")
{
responseStream = new System.IO.Compression.DeflateStream(response.GetResponseStream(), System.IO.Compression.CompressionMode.Decompress);
}
else
{
responseStream = response.GetResponseStream();
}
StreamReader sr = new StreamReader(responseStream, encode);
strResult = sr.ReadToEnd();
}
catch
{
//dosomething
}
finally
{
response.Close();
}
return strResult;
}
}
调用示例：
static void Main(string[] args)
{
string userName = "lxnanhr";
string userPwd = "lxnanhr";
string content = LogingHelper.Login("http://www.aa.com/index.php?c=login&m=chklogin", "uname=xxx&pass=xxx", "http://www.aa.com/index.php?c=login");
Console.WriteLine(content);
Console.WriteLine(LogingHelper.getPage("http://www.aa.com/index.php?c=preview&m=view&resume_id=1179406405&keyword=", "http://www.aa.com/index.php?c=search&m=supersearch#"));
Console.ReadLine();
}