c# 使用 HttpWebRequest模拟登陆（附带验证码）

在C#中，可以使用HttpWebRequest进行相关的模拟登陆，登陆后进行相关的操作，比如抓取数据，页面分析，***相关登陆助手等等。

先说下流程

1.使用httpwebrequest先进入你要登录的网站，获取cookie

2.使用第一步获取的cookie到验证码的网页将验证码下载下来。

3.使用Post数据 发送至网站。如果有cookie则继续保存。

4.使用第三步的cookie登陆相关网页操作。



获取相关数据可以使用抓包工具进行抓取，如httpwatch。（网上下载的好多都有病毒，下载的时候注意点）

/// <summary>

/// 通过get方式请求页面，传递一个实例化的cookieContainer

/// </summary>

/// <param name="postUrl"></param>

/// <param name="cookie"></param>

/// <returns></returns>

public static ArrayList GetHtmlData(string postUrl, CookieContainer cookie)

{

HttpWebRequest request;

HttpWebResponse response;

ArrayList list = new ArrayList();

request = WebRequest.Create(postUrl) as HttpWebRequest;

request.Method = "GET";

request.UserAgent = "Mozilla/4.0";

request.CookieContainer = cookie;

request.KeepAlive = true;

request.CookieContainer = cookie;

try

{

//获取服务器返回的资源

using (response = (HttpWebResponse)request.GetResponse())

{

using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.Default))

{

cookie.Add(response.Cookies);

//保存Cookies

list.Add(cookie);

list.Add(reader.ReadToEnd());

list.Add(Guid.NewGuid().ToString());//图片名

}

}

}

catch (WebException ex)

{

list.Clear();

list.Add("发生异常/n/r");

WebResponse wr = ex.Response;

using (Stream st = wr.GetResponseStream())

{

using (StreamReader sr = new StreamReader(st, System.Text.Encoding.Default))

{

list.Add(sr.ReadToEnd());

}

}

}

catch (Exception ex)

{

list.Clear();

list.Add("5");

list.Add("发生异常：" + ex.Message);

}

return list;

}

2.下载验证码，保存在本地。

/// <summary>

/// 下载验证码图片并保存到本地

/// </summary>

/// <param name="Url">验证码URL</param>

/// <param name="cookCon">Cookies值</param>

/// <param name="savePath">保存位置/文件名</param>

public static bool DowloadCheckImg(string Url, CookieContainer cookCon, string savePath)

{

bool bol = true;

HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(Url);

//属性配置

webRequest.AllowWriteStreamBuffering = true;

webRequest.Credentials = System.Net.CredentialCache.DefaultCredentials;

webRequest.MaximumResponseHeadersLength = -1;

webRequest.Accept = "image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*";

webRequest.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; Maxthon; .NET CLR 1.1.4322)";

webRequest.ContentType = "application/x-www-form-urlencoded";

webRequest.Method = "GET";

webRequest.Headers.Add("Accept-Language", "zh-cn");

webRequest.Headers.Add("Accept-Encoding", "gzip,deflate");

webRequest.KeepAlive = true;

webRequest.CookieContainer = cookCon;

try

{

//获取服务器返回的资源

using (HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse())

{

using (Stream sream = webResponse.GetResponseStream())

{

List<byte> list = new List<byte>();

while (true)

{

int data = sream.ReadByte();

if (data == -1)

break;

list.Add((byte)data);

}

File.WriteAllBytes(savePath, list.ToArray());

}

}

}

catch (WebException ex)

{

bol = false;

}

catch (Exception ex)

{

bol = false;

}

return bol;

}

3。发送post数据

/// <summary>

/// 发送相关数据至页面

/// 进行登录操作

/// 并保存cookie

/// </summary>

/// <param name="postData"></param>

/// <param name="postUrl"></param>

/// <param name="cookie"></param>

/// <returns></returns>

public static ArrayList PostData(string postData, string postUrl, CookieContainer cookie)

{

ArrayList list = new ArrayList();

HttpWebRequest request;

HttpWebResponse response;

ASCIIEncoding encoding = new ASCIIEncoding();

request = WebRequest.Create(postUrl) as HttpWebRequest;

byte[] b = encoding.GetBytes(postData);

request.UserAgent = "Mozilla/4.0";

request.Method = "POST";

request.CookieContainer = cookie;

request.ContentLength = b.Length;

using (Stream stream = request.GetRequestStream())

{

stream.Write(b, 0, b.Length);

}

try

{

//获取服务器返回的资源

using (response = request.GetResponse() as HttpWebResponse)

{

using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))

{

if (response.Cookies.Count > 0)

cookie.Add(response.Cookies);

list.Add(cookie);

list.Add(reader.ReadToEnd());

}

}

}

catch (WebException wex)

{

WebResponse wr = wex.Response;

using (Stream st = wr.GetResponseStream())

{

using (StreamReader sr = new StreamReader(st, System.Text.Encoding.Default))

{

list.Add(sr.ReadToEnd());

}

}

}

catch (Exception ex)

{

list.Add("发生异常/n/r"+ex.Message);

}

return list;

}

4。就是第三步请求的链接地址换一个就行了



好了

以上核心代码已经贴出了

具体实现需要靠你们按照你们自己的逻辑



还有一些header能不写就不写，因为我2天前一直在获取返回response这地方报500错误。

找了N多代码，看了N多资料都不可以。最后将一些header注释掉就可以了，真郁闷。