如何从aspx网站__doPostBack表单中抓取数据

Question

我正在尝试使用c#控制台应用程序抓取网站，获取初始页面不是问题，但我需要在单击具有__doPostBack操作的按钮时获取页面。

我尝试使用这些设置，但这已经从初始页面返回了结果：

我更新我的代码

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);

Answer 1

使用RestRequest.AddParameter而不是RestRequest.AAddHeader

https://csharp.hotexamples.com/examples/RestSharp/RestRequest/AddHeader/php-restrequest-addheader-method-examples.html

https://csharp.hotexamples.com/examples/RestSharp/RestRequest/AddParameter/php-restrequest-addparameter-method-examples.html