利用HttpWebRequest抓取网页数据

HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);
Encoding encoding = Encoding.UTF8;
string param = "muMailNum=" + mailCode + "&checkCode=" + code;
byte[] bs = Encoding.ASCII.GetBytes(param);

req.Method = "POST";
req.Timeout = 30000;
req.ContentType = "application/x-www-form-urlencoded";
req.ContentLength = bs.Length;
req.CookieContainer = _cookieCon;
using (Stream reqStream = req.GetRequestStream())
{
reqStream.Write(bs, 0, bs.Length);
reqStream.Close();
}
using (HttpWebResponse response = (HttpWebResponse)req.GetResponse())
{
using (StreamReader reader = new StreamReader(response.GetResponseStream(), encoding))
{
responseData = reader.ReadToEnd().ToString();
}
}