C# 搜狗鏈接網址轉換為真實網址

一、問題：

當我們拿到百度某個鏈接時，顯示的是一個鏈接https://www.sogou.com/link?url=xxx，跳轉后的鏈接是：https://baike.sogou.com/xxx

　　例：

　　　　原鏈接：https://www.sogou.com/link?url=DOb0bgH2eKjRiy6S-EyBciCDFRTZxEJg9BcDwvTo02r26FDhCNBXEOt74PAtEBpptz5XqOoFKPCt5pUc3zy0dg..

　　　　跳轉后的鏈接：https://baike.sogou.com/v7677690.htm?fromTitle=text%28%29

這里我們需要得到跳轉后的鏈接，此方法也可用於360搜索鏈接轉換

二、代碼

添加Nuget：HtmlAgilityPack程序包

引用：using HtmlAgilityPack;

        public static string ResultOfApi(string url)
        {
            //發送請求
            HttpWebRequest request = null;
            HttpWebResponse response = null;
            request = (HttpWebRequest)HttpWebRequest.Create(url);
            request.Method = "Get";
            request.ContentType = "application / x - www - form - urlencoded";
            request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36";
            request.Accept = "text / html,application / xhtml + xml,application / xml; q = 0.9,image / webp,image / apng,*/*;q=0.8";
            request.KeepAlive = true;
            //獲取響應
            response = (HttpWebResponse)request.GetResponse();
            Stream S = response.GetResponseStream();
            StreamReader streamreader = new StreamReader(S);
            string result = streamreader.ReadToEnd();
            response.Close();
            //加載源代碼，獲取文檔對象
            var doc = new HtmlDocument(); doc.LoadHtml(result);
            string text_XPath = @"/script[1]";
            var text_list = doc.DocumentNode.SelectSingleNode(text_XPath);
            string newUrl = text_list.InnerHtml.Substring(text_list.InnerHtml.IndexOf('"') + 1);
            newUrl = newUrl.Remove(newUrl.LastIndexOf('"'));return newUrl;
        }