使用HtppWebRequest发布表单数据没有效果
我遇到了一个看起来非常简单的网站,我非常确信,我将能够使用HttpWebRequest读取它的数据,并能够执行GET和POST请求。 GET请求工作正常。 POST请求也不会产生任何错误,但发布的表单数据仍然不会影响返回的结果。 发布的表单数据具有根据日期过滤数据的字段,但无论发布每个所需数据的事实如何,都不会过滤返回的数据。 我添加了每个标题,表单数据并在请求中添加了Cookie。
该网页的网址是http://www.bseindia.com/corporates/Insider_Trading_new.aspx?expandable=0
这看起来像一个非常普通的网站,但是因为它是一个aspx页面,并且涉及ViewState和Event Validation,因此预计这不太容易。
我的第一步是使用Fiddler分析网站的GET和POST,这让我感到惊讶,因为Fiddler没有捕获此网址的任何流量。 我曾尝试查尔斯,但它本身并没有捕获这个网址。 除此之外,这位Url Fiddler和Charles都在捕捉其他一切。 我还想提一下,当我使用HttpWebRequest从控制台应用程序调用Url时,Fiddler和Charles都捕获了它,但它们没有从Chrome,FireFox和Internet Explorer 11中捕获它。
因此,我使用FireFox中的开发人员工具分析了网络活动,并且所有内容都可见,其中包括(标题,参数和Cookie)。 在Chrome中没有Cookie存在。 当我通过创建HttpWebRequest来检查cookie并获得响应时,不存在cookie。 所以,在这个网站上有些奇怪的事情。
我不知何故设法创建一个简单的函数来创建请求并获得响应。 我所做的是我首先创建一个GET请求,并获取网站字符串并从中提取Viewstate,EventValidation等。 我使用这个信息被用于第二个HttpWebRequest这是一个帖子。 现在一切正常,我得到的回应,但不是预期的。 我想要两个给定日期之间的记录,并且我已经在表单数据中指定了这些日期,但POST请求仍然不会返回过滤的数据。 我已经提到了我在下面创建的函数,我将非常感谢任何建议,为什么会发生这种情况以及如何处理此问题。 要理解这一点已经成为我的一个挑战,因为我不明白为什么这个简单的网站没有出现在小提琴手中。 (这使用JavaScript回发)
代码可能看起来漫长而可怕,但它非常简单直接。
Try
' First GET Request to obtain Viewstate, Eventvalidation etc
Dim objRequest2 As Net.HttpWebRequest = DirectCast(HttpWebRequest.Create("http://www.bseindia.com/corporates/Insider_Trading_new.aspx?expandable=0"), HttpWebRequest)
objRequest2.Method = "GET"
objRequest2.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"
objRequest2.Headers.Add("Accept-Encoding", "gzip, deflate")
objRequest2.Headers.Add("Accept-Language", "en-GB,en-US;q=0.8,en;q=0.6,ur;q=0.4")
objRequest2.KeepAlive = True
objRequest2.ContentType = "application/x-www-form-urlencoded"
objRequest2.Host = "www.bseindia.com"
objRequest2.UserAgent = "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.106 Safari/537.36"
objRequest2.AutomaticDecompression = DecompressionMethods.Deflate Or DecompressionMethods.GZip
Dim LoginRes2 As Net.HttpWebResponse
Dim sr2 As IO.StreamReader
LoginRes2 = objRequest2.GetResponse()
sr2 = New IO.StreamReader(LoginRes2.GetResponseStream)
Dim getString As String = sr2.ReadToEnd()
Dim getCookieCollection = objRequest2.CookieContainer
' get the page ViewState
Dim viewStateFlag As String = "id=""__VIEWSTATE"" value="""
Dim i As Integer = getString.IndexOf(viewStateFlag) + viewStateFlag.Length
Dim j As Integer = getString.IndexOf("""", i)
Dim viewState As String = getString.Substring(i, j - i)
' get page EventValidation
Dim eventValidationFlag As String = "id=""__EVENTVALIDATION"" value="""
i = getString.IndexOf(eventValidationFlag) + eventValidationFlag.Length
j = getString.IndexOf("""", i)
Dim eventValidation As String = getString.Substring(i, j - i)
' get page EventValidation
Dim viewstateGeneratorFlag As String = "id=""__VIEWSTATEGENERATOR"" value="""
i = getString.IndexOf(viewstateGeneratorFlag) + viewstateGeneratorFlag.Length
j = getString.IndexOf("""", i)
Dim viewStateGenerator As String = getString.Substring(i, j - i)
viewState = System.Web.HttpUtility.UrlEncode(viewState)
eventValidation = System.Web.HttpUtility.UrlEncode(eventValidation)
Dim LoginRes As Net.HttpWebResponse
Dim sr As IO.StreamReader
Dim objRequest As Net.HttpWebRequest
' Second POST request to post the form data along with cookies
objRequest = DirectCast(HttpWebRequest.Create("http://www.bseindia.com/corporates/Insider_Trading_new.aspx?expandable=0"), HttpWebRequest)
Dim formDataCollection As New NameValueCollection
formDataCollection.Add("__EVENTTARGET", "")
formDataCollection.Add("__EVENTARGUMENT", "")
formDataCollection.Add("__VIEWSTATE", viewState)
formDataCollection.Add("__VIEWSTATEGENERATOR", viewStateGenerator)
formDataCollection.Add("__EVENTVALIDATION", eventValidation)
formDataCollection.Add("fmdate", "20160104")
formDataCollection.Add("eddate", "20160204")
formDataCollection.Add("hidCurrentDate", "2016/02/04")
formDataCollection.Add("ctl00_ContentPlaceHolder1_hdnCode", "")
formDataCollection.Add("txtDate", "04/01/2016")
formDataCollection.Add("ddlCalMonthDiv3", "1")
formDataCollection.Add("ddlCalYearDiv3", "2016")
formDataCollection.Add("txtTodate", "04/02/2016")
formDataCollection.Add("ddlCalMonthDiv4", "2")
formDataCollection.Add("ddlCalYearDiv4", "2016")
formDataCollection.Add("Hidden1", "")
formDataCollection.Add("ctl00_ContentPlaceHolder1_GetQuote1_smartSearch", "Enter Security Name / Code / ID")
formDataCollection.Add("btnSubmit.x", "44")
formDataCollection.Add("btnSubmit.y", "2")
Dim strFormdata As String = formDataCollection.ToString()
Dim encoding As New ASCIIEncoding
Dim postBytes As Byte() = encoding.GetBytes(strFormdata)
objRequest.Method = "POST"
objRequest.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"
objRequest.Headers.Add("Accept-Encoding", "gzip, deflate")
objRequest.Headers.Add("Accept-Language", "en-GB,en-US;q=0.8,en;q=0.6,ur;q=0.4")
objRequest.Headers.Add("Cache-Control", "private, max-age=60")
objRequest.KeepAlive = True
objRequest.ContentType = "application/x-www-form-urlencoded"
objRequest.Host = "www.bseindia.com"
objRequest.Headers.Add("Origin", "http://www.bseindia.com")
objRequest.Referer = "http://www.bseindia.com/corporates/Insider_Trading_new.aspx?expandable=0"
objRequest.Headers.Add("Upgrade-Insecure-Requests", "1")
objRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.106 Safari/537.36"
objRequest.ContentType = "text/html; charset=utf-8"
objRequest.Date = "Thu, 04 Feb 2016 13:42:04 GMT"
objRequest.Headers.Add("Server", "Microsoft-IIS/8.0")
objRequest.Headers.Add("Vary", "Accept-Encoding")
objRequest.Headers.Add("X-AspNet-Version", "2.0.50727")
objRequest.Headers.Add("ASP.NET", "ASP.NET")
objRequest.AutomaticDecompression = DecompressionMethods.Deflate Or DecompressionMethods.GZip
Dim gaCookies As New CookieContainer()
Dim cookie1 As New Cookie("__asc", "f673f0d5152a823bc335f575d34")
cookie1.Domain = ".bseindia.com"
cookie1.Path = "/"
gaCookies.Add(cookie1)
Dim cookie2 As New Cookie("__auc", "f673f0d5152a823bc335f575d34")
cookie2.Domain = ".bseindia.com"
cookie2.Path = "/"
gaCookies.Add(cookie2)
Dim cookie3 As New Cookie("__utma", "253454874.280640365.1454519857.1454519865.1454519865.1")
cookie3.Domain = ".bseindia.com"
cookie3.Path = "/"
gaCookies.Add(cookie3)
Dim cookie4 As New Cookie("__utmb", "253454874.1.10.1454519865")
cookie4.Domain = ".bseindia.com"
cookie4.Path = "/"
gaCookies.Add(cookie4)
Dim cookie5 As New Cookie("__utmc", "253454874")
cookie5.Domain = ".bseindia.com"
cookie5.Path = "/"
gaCookies.Add(cookie5)
Dim cookie6 As New Cookie("__utmt", "1")
cookie6.Domain = ".bseindia.com"
cookie6.Path = "/"
gaCookies.Add(cookie6)
Dim cookie7 As New Cookie("__utmz", "253454874.1454519865.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)")
cookie7.Domain = ".bseindia.com"
cookie7.Path = "/"
gaCookies.Add(cookie7)
Dim cookie8 As New Cookie("_ga", "GA1.2.280640365.1454519857")
cookie8.Domain = ".bseindia.com"
cookie8.Path = "/"
gaCookies.Add(cookie8)
Dim cookie9 As New Cookie("_gat", "1")
cookie9.Domain = ".bseindia.com"
cookie9.Path = "/"
gaCookies.Add(cookie9)
Dim postStream As Stream = objRequest.GetRequestStream()
postStream.Write(postBytes, 0, postBytes.Length)
postStream.Flush()
postStream.Close()
LoginRes = objRequest.GetResponse()
sr = New IO.StreamReader(LoginRes.GetResponseStream)
ReadWebsite = sr.ReadToEnd()
sr.Close()
sr = Nothing
LoginRes.Close()
LoginRes = Nothing
objRequest = Nothing
Exit Function
Catch ex As Exception
ReadWebsite = Nothing
End Try
注意:(没有viewstate和eventvalidation的日期的原始表单数据)
fmdate:20160130 eddate:20160205 hidCurrentDate:2016/02/05 ctl00_ContentPlaceHolder1_hdnCode:txtDate:04/01/2016 ddlCalMonthDiv3:1 ddlCalYearDiv3:2016 txtTodate:04/02/2016 ddlCalMonthDiv4:2 ddlCalYearDiv4:2016隐藏1:ctl00_ContentPlaceHolder1_GetQuote1_smartSearch:输入安全名称/代码/ ID btnSubmit.x:55 btnSubmit.y:13
您可以考虑在浏览器中运行网站,并使用工具来控制浏览器,而不是直接发出GET / POST请求。 这可能比您现在的方法更容易,也更健壮一些。
例如Selenium Web驱动程序http://www.seleniumhq.org/projects/webdriver/
您可以加载页面,设置表单字段的值(使用CSS样式选择器来查找相应的字段),然后单击按钮。 你可以自动化所有这些并获得页面源代码(不幸的是,我不认为你可以在javascript运行之后获得当前状态的完整html,但是可能你可以使用api来获取你需要的元素)。
Api文档:http://seleniumhq.github.io/selenium/docs/api/dotnet/
您确实应该包含表单中的所有字段,包括存储在Cookie中的隐藏字段和ASP会话标识符。 这样你完全模拟浏览器的请求并实现你的目标。 要显示您必须提交的内容 - http://pastebin.com/AsSABgU6
链接地址: http://www.djcxy.com/p/31939.html