使用HtppWebRequest发布表单数据没有效果

Question

使用HtppWebRequest发布表单数据没有效果

我遇到了一个看起来很简单的网站,我非常有信心能够使用HttpWebRequest读取数据并能够执行GET和POST请求.GET请求工作正常.POST请求也不会产生任何错误,但仍然发布的表单数据对返回的结果没有影响.发布的表单数据具有按日期过滤数据的字段,但无论是否发布了所有必需数据,都不会过滤返回的数据.我添加了每个标题,表单数据以及添加了请求的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,但由于它是一个aspx页面,涉及ViewState和事件验证,因此预计这不会很容易.

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没有为这个网址捕获任何流量.我试过查尔斯,但这本身并没有抓住这个网址.除此之外,这个Url Fiddler和Charles都捕获了其他一切.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,但他们没有从Chrome,FireFox和Internet Explorer 11捕获它.

因此,我使用FireFox中的开发人员工具分析了网络活动,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检查cookie并得到响应时,没有cookie存在.所以这个网站真的很奇怪.

我以某种方式设法创建一个简单的函数来创建请求并获得响应.我正在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.我使用此信息在第二个HttpWebRequest中使用,这是一个帖子.现在一切正常,我收到的回复却不如预期.我想要两个给出日期之间的记录,我已经在表单数据中指定了这些日期,但POST请求仍然不返回过滤后的数据.我已经提到了我在下面创建的函数,我将非常感谢为什么会发生这种情况以及如何处理它的任何建议.要理解这一点对我来说是一个挑战,因为我无法理解为什么这个简单的网站没有出现在Fiddler中.(这使用Javascript Postback)

代码可能看起来很长而且很可怕,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

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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 Hidden1:ctl00_ContentPlaceHolder1_GetQuote1_smartSearch:输入安全名称/代码/ ID btnSubmit.x:55 btnSubmit.y:13

Answer 1

小智 2

您可以考虑在浏览器中运行该站点并使用工具来控制浏览器，而不是直接发出 GET/POST 请求。这可能比您当前的方法更容易、更稳健。

例如 Selenium Web 驱动程序http://www.seleniumhq.org/projects/webdriver/

您将加载页面，设置表单字段的值（使用 css 样式选择器查找适当的字段），然后单击按钮。您可以自动化所有这些并获取页面源（不幸的是，我认为在 javascript 运行后，您无法获取当前状态下的完整 html，但您可能可以使用 api 来获取所需的元素）。

API文档：http://seleniumhq.github.io/selenium/docs/api/dotnet/

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