c#获取网页源代码

/// <summary>
/// 获取html信息
/// </summary>
private string GetHtmlText(string url)
{
WebRequest req = WebRequest.Create(url);
WebResponse res = req.GetResponse();
Stream resStream = res.GetResponseStream();
StreamReader sr = new StreamReader(resStream, Encoding.UTF8);
string contentHtml = sr.ReadToEnd();    //读取网页的源代码
return contentHtml;
}