C#-网络请求方法

 class Crawler_Method
    {
        public static Dictionary<String, String> GETCity()
        {
            String html=GET("https://www.zhaopin.com/citymap.html");//调用网络请求函数
            
            return Parse1(html);//调用解析函数解析网页得到数据
        }
        public static Dictionary<String, String> Parse1(String html)
        {
            Dictionary<String, String> map = new Dictionary<string, string>();
            Document doc = NSoup.NSoupClient.Parse(html);//将网页返回的数据用Nsoup初始化为document文档进行结构初始化
            Elements elements = doc.GetElementsByClass("col1");//得到属性class为col1的元素
            Elements e = elements[0].Select("a");//得到tag为a的元素
            for (int x=0;x<e.Count;x++)//对得到的多个a  进行循环获得数据
            {
                Element a = e[x];
                if(a.Attr("href").Substring(2).StartsWith("www"))//得到目标数据
                map.Add(a.Text(), "https://" + a.Attr("href").Substring(2));
            }
            return map;
        }


        public static Dictionary<String, String> GetCompany(String url)
        {
            String html = GET(url);

            return Parse2(html);
        }
        public static Dictionary<String, String> Parse2(String html)//此方法注释与上同
        {
            Dictionary<String, String> map = new Dictionary<string, string>();
            Document doc = NSoup.NSoupClient.Parse(html);
            Elements elements = doc.GetElementsByClass("nctt");
            Elements e = elements[0].Select("li");
            for (int x = 0; x < e.Count; x++)
            {
             
                Element a = e[x];
                map.Add(a.Select("a")[0].Text(),a.Select("a")[0].Attr("href"));
            }
            return map;
        }
        public static String GET(String share_url)
        {
            
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(share_url);//通过网页链接对网络请求类进行初始化
            request.Method = "GET";//设置请求方式为get
            request.AllowAutoRedirect = true;//允许网页重定向
            // request.Headers.Set("Content-Range", " bytes 0 - 126399 / 8065760");
            request.UserAgent = "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36 SE 2.X MetaSr 1.0";
            //反爬虫的设置  设置浏览器标识

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();//得到网页返回reponse对象
            //Console.WriteLine(response.Headers.ToString());
            Stream stream = response.GetResponseStream();//得到网页输出流  
            StreamReader read = new StreamReader(stream, System.Text.Encoding.GetEncoding("utf-8"));//对返回的数据进行解码
            String nextline = "";
            String html = "";
            while ((nextline = read.ReadLine()) != null)//不断地读取输入流,读取网页源码
            {
                html += nextline;
            }
            read.Close();
            return html;//返回网页源码
        }
    }