C#获取网页源代码的方法

public string GetPageHTML(string url)
{
 try
 {
  HttpWebRequest wr = WebRequest.Create(url) as HttpWebRequest;
  wr.Method = "get";
  wr.Accept = "*/*";
  wr.Headers.Add("Accept-Language: zh-cn");
  wr.Headers.Add("UA-CPU: x86");
  wr.Headers.Add("Accept-Encoding: gzip, deflate");
  wr.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Embedded Web Browser from: http://bsalsa.com/; InfoPath.2; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022)";
  wr.KeepAlive = true;
  wr.ServicePoint.Expect100Continue = false;
  wr.AllowAutoRedirect = false;
  HttpWebResponse wre = wr.GetResponse() as HttpWebResponse;
  StreamReader sreader = new StreamReader(wre.GetResponseStream(), Encoding.GetEncoding("GBK"));
  string sHtml = sreader.ReadToEnd();
  wre.Close();
  return sHtml;
 }
 catch
 {
  return "";
 }
}