我正在尝试使用c＃控制台应用程序爬网/抓取网站，获取初始页面不是问题，但是当我单击具有__doPostBack操作的按钮时，我需要获取页面。

我尝试使用这些设置，但这已经从初始页面返回结果：

我更新代码

            var client1 = new RestClient("https://example.com");
            var request1 = new RestRequest(Method.POST);
            IRestResponse initialResponse = client1.Execute(request1);


            HtmlDocument doc = new HtmlDocument();
            doc.LoadHtml(initialResponse.Content);

            var formData = new Dictionary<string,string>();
            formData.Add("__EVENTTARGET","ctl00$MainContentExample");
            formData.Add("__EVENTARGUMENT","");
            formData.Add("ctl00$MainContent$CustomHiddenField","");
            formData.Add("__VIEWSTATEGENERATOR","B5682C7D");
            var divViewState = doc.DocumentNode
                .SelectSingleNode("//input[@name='__VIEWSTATE']").Attributes[3].Value;
            formData.Add("__VIEWSTATE",divViewState);
            var divEventValidation = doc.DocumentNode
                .SelectSingleNode("//input[@name='__EVENTVALIDATION']").Attributes[3].Value;
            formData.Add("__EVENTVALIDATION",divEventValidation);


            var client = new RestClient("https://example.com");
            var request = new RestRequest("/methodName",Method.POST);
            request.AddHeader("cache-control","no-cache");
            request.AddHeader("Connection","keep-alive");

            var c = "";
            var i = 0;
            foreach (var cookie in initialResponse.Cookies)
            {
                if(i==0)
                 c += cookie.Name + "=" + cookie.Value + "; ";
                else
                    c += cookie.Name + "=" + cookie.Value;

                i++;
            }
            request.AddHeader("Cookie",c);
           request.AddHeader("accept-Encoding","gzip,deflate,br");
            request.AddHeader("Host","example.com");
            request.AddHeader("Cache-Control","max-age=0");
            request.AddHeader("accept","text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3");
            request.AddHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML,like Gecko) Chrome/78.0.3904.108 Safari/537.36");
            request.AddHeader("Content-Type","application/x-www-form-urlencoded");
            request.AddHeader("accept-Language","en-US,en;q=0.9");
            request.AddHeader("Content-Encoding","utf-8");

            var json = JsonConvert.SerializeObject(formData);
            byte[] byteData = Encoding.UTF8.GetBytes(json);

            request.AddHeader("Content-Length",byteData.Length.ToString())


            request.AddParameter("undefined",byteData,ParameterType.RequestBody);

            IRestResponse response2 = client.Execute(request);