C# 访问网页并对页面上的元素进行抓取

//
HttpWebRequest request=HttpWebRequest.Create(“URL”) AS HttpWebRequest;

//设置访问页面的标头
request.Method = “get”;//通过get方式访问
//在需访问的页面F12,Network下的Headers中可以查看
request.Accept = “”;
request.ContentType = “”;
request.UserAgent = “”;

HttpWebResponse response = request.GetResponse() as HttpWebResponse;

StreamReader steamReader=new SteamReader(response.GetResponseStream());

//如果请求下来的页面是zip格式
Stream ResStream = new System.IO.Compression.GZipStream(response.GetResponseStream(), System.IO.Compression.CompressionMode.Decompress);
Encoding encoding = Encoding.GetEncoding(“utf-8”);
StreamReader streamReader = new StreamReader(ResStream, encoding);

//请求下来的HTML页面
String data=stream.ReadToEnd();

//以携程网主页房间数为例

        Hashtable hashtable = new Hashtable();// 网页中元素对象
        var htmlDoc = new HtmlAgilityPack.HtmlDocument();
        htmlDoc.LoadHtml(data);//解析
         
        HtmlNode token = htmlDoc.DocumentNode.SelectSingleNode(Xpath);
        
        List li = new List();
        
		//遍历其中符合条件的数据
        foreach (HtmlNode row in token.SelectNodes("option"))
        {
            li.Add(row.InnerHtml);
        }
        
        String aa=string.Empty;
        for (int i=0;i

//显示爬取下来的数据aa