/// <summary>
/// 获取网页HTML源码
/// </summary>
/// <param name="url">链接 eg:http://www.baidu.com/ </param>
/// <param name="charset">编码 eg:Encoding.UTF8</param>
/// <returns>HTML源码</returns>
public static string GetHtmlSource(string url, Encoding charset)
{

    string _html = string.Empty;
    try
    {
 HttpWebRequest _request = (HttpWebRequest)WebRequest.Create(url);
 HttpWebResponse _response = (HttpWebResponse)_request.GetResponse();
 using (Stream _stream = _response.GetResponseStream())
 {
     using (StreamReader _reader = new StreamReader(_stream, charset))
     {
  _html = _reader.ReadToEnd();
     }
 }
    }
    catch (WebException ex)
    {
 using (StreamReader sr = new StreamReader(ex.Response.GetResponseStream()))
 {
     _html = sr.ReadToEnd();
 }
    }
    catch (Exception ex)
    {
 _html = ex.Message;
    }
    return _html;
}

public static void GetHtmlSourceTest()
{
    string _url = "http://www.baidu.com/";
    string _htmlSource = HttpWebRequestUtilsV2.GetHtmlSource(_url, Encoding.UTF8);
    Console.WriteLine(_htmlSource);
}