抓取页面源代码

    private string GetPageCodes(string Url)
    {
        string strHtml = "";
        WebRequest web = WebRequest.Create(Url);
        //WebResponse hwr = web.GetResponse();
        HttpWebResponse hwr = (HttpWebResponse)web.GetResponse();
        //采用流读取，并确定编码方式  
        Stream s = hwr.GetResponseStream();
        StreamReader objReader = new StreamReader(s, Encoding.Default);
        string strLine = "";
        while (strLine != null)
        {
            strLine = objReader.ReadLine();
            if (strLine != null)
            {
                strHtml += strLine;
            }
        }
        return strHtml;
    }