The necessary references to System.Web and the Impports statement are already in the DLL
In code behind you can do this:
Dim MyString As String = Request.UserAgent
but transfer that code into a DLL and it's no good. I cannot seem to define ServerVariables("HTTP_USER_AGENT") either.
I have even tried this
Dim wr As System.Web.HttpRequest = New Web.HttpRequest(Nothing, Nothing, Nothing)
Dim s As String = wr.UserAgent
but get an error Object Not Set... If I add a URL for the middle value as I don't require a Filename or a QueryString, no luck either.
Dim wr As System.Web.HttpRequest = New Web.HttpRequest(Nothing, "https://stackoverflow.com", Nothing)
Dim s As String = wr.UserAgent
How can I return the visitors UserAgent using code from a DLL an NOT Code Behind, please? I have checked for this answer on this site and couldn't find one.
When outside of code-behind you can do this:
Dim MyString As String = HttpContext.Current.Request.UserAgent
HttpContext.Current also has properties for Response, Server, Session, and plenty of other useful values.
Related
I have found good information on how to automatically download a file to the client advertised as a solution of how to print using code
(https://forums.asp.net/t/1233841.aspx?How+do+I+print+from+Reporting+Services+AUTOMATICALLY+in+VB+Net+web+app+)
but what I need to do is have the code print the document without the user interacting.
From what I have found it appears this can not be done as one might casually think. ReportViewer for example does not have a 'print' method.
The only two solutions appears to be to use ProcessStart (which then means saving the file to the file system before printing which I dont want to do)
or maybe (will be researching this today) create a subscription using code and then delete it later.
You are not able to print a report directly from your asp.net page. The reason for this is security. If it allowed you to send a file through the network and onto the clients computer, and then search the computer for a printer, this could cause major security issues. The report viewer does have a print icon, but this disappears when you deploy the project and run the page remotely. I have faced the same issue in the past and found it best to just export the report to say PDF and allow the user to Download it. I have used the below code to accomplish this task in the past:
Private Sub CreatePDFMatrix(fileName As String)
' ReportViewer1.LocalReport.DataSources.Clear()
Dim adapter As New ReportDataSetTableAdapters.vwPrintTagsTableAdapter
Dim table As New ReportDataSet.vwPrintTagsDataTable
Dim month = MonthName(Date.Today.Month)
Dim year = Date.Today.Year
Dim p(1) As ReportParameter
Dim warnings() As Warning
Dim streamIds As String()
Dim mimeType As String = String.Empty
Dim encoding As String = String.Empty
Dim extension As String = String.Empty
Dim adpt2 As New ReportDataSetTableAdapters.vwPrintTagsTableAdapter
adapter.FillForMainReport(table, DropDownList1.SelectedValue, g_Company, g_Division)
Me.ReportViewer1.LocalReport.DataSources.Add(New ReportDataSource("DataSet1", CType(table, DataTable))) 'Add(New ReportDataSource("ReportingData", CType(table, DataTable)))
Me.ReportViewer1.DataBind()
Dim viewer = ReportViewer1
viewer.ProcessingMode = ProcessingMode.Local
viewer.LocalReport.ReportPath = "Report1.rdlc"
p(0) = New ReportParameter("MonthYear", month & "-" & year)
Dim check = DropDownList1.SelectedValue
ReportViewer1.LocalReport.SetParameters(p(0))
p(1) = New ReportParameter("Location", DropDownList1.SelectedValue)
ReportViewer1.LocalReport.SetParameters(p(1))
Try
Dim bytes As Byte() = viewer.LocalReport.Render("PDF", Nothing, mimeType, encoding, ".pdf", streamIds, warnings)
Response.Buffer = True
Response.Clear()
Response.ContentType = mimeType
Response.AddHeader("content-disposition", Convert.ToString((Convert.ToString("attachment; filename=") & fileName) + ".") & extension)
Response.BinaryWrite(bytes)
' create the file
Response.Flush()
Catch ex As Exception
Debug.Print(ex.ToString)
End Try
End Sub
I've seen several questions relating to downloading a PDF from a Web browser using Response, but none seem to fit the mysterious issue I'm having.
I am working on a project that requires the user to be able to click a button (btnPDF) to instantly download a PDF of a Telerik report with a specific "ID" string to the Downloads folder. This process was originally located in an ASPX Page on an IIS separate from where the button is located. When btnPDF was clicked, I used Response.Redirect to download the PDF through that page. The code to download the PDF looked like this:
Response.Clear()
Response.ContentType = result.MimeType 'this is always "application/pdf"
Response.Cache.SetCacheability(HttpCacheability.Private)
Response.Expires = -1
Response.Buffer = True
Response.AddHeader("Content-Disposition", String.Format("{0};FileName={1}", "attachment", fileName))
Response.BinaryWrite(result.DocumentBytes)
Response.End()
Note that result.DocumentBytes is a byte array containing correct bytes for the PDF.
This code worked fine. Now, instead of having the process on a separate Page in a separate project, I need to merge the process onto the same page where btnPDFis located, so that when you click btnPDF, a subroutine is called that performs the same task. I thought this would be very easy, pretty much a copy and paste. With the same code added in a new subroutine, this is what my click event handler "ButtonPDF_Click" now looks like:
Protected Sub ButtonPDF_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnPDF.Click
DownloadReportPDF(Me.RadGrid1.SelectedValue.ToString())
Dim strMessage As String = "alert('Printed PDF Sheet.');"
ScriptManager.RegisterStartupScript(Me, Me.GetType, "MyScript", strMessage, True)
End Sub
Protected Sub DownloadReportPDF(ByVal releaseMasterId As String)
'Service call to generate report source
Dim service As New TelerikReportLibrary.ReportServices.PPSReportService
Dim source As Telerik.Reporting.TypeReportSource = service.GetReportSource(releaseMasterId)
'Render PDF and download
Dim reportProcessor As New ReportProcessor()
Dim result As RenderingResult = reportProcessor.RenderReport("PDF", source, Nothing)
Dim fileName As String = result.DocumentName + "_" + releaseMasterId + "." + result.Extension
Response.Clear()
Response.ContentType = result.MimeType 'this is always "application/pdf"
Response.Cache.SetCacheability(HttpCacheability.Private)
Response.Expires = -1
Response.Buffer = True
Response.AddHeader("Content-Disposition", String.Format("{0};FileName={1}", "attachment", fileName))
Response.BinaryWrite(result.DocumentBytes)
Response.End()
End Sub
But the PDF no longer downloads. An accurate byte array is still created, but the Response portion does not result in the PDF being downloaded from the browser. I've found that putting a call to DownloadReportPDF in the Page_Load handler on the same Page successfully generates and downloads a PDF as it did before.
I can't see any reason why this isn't working, but I'm new to ASP, and I'm not great in VB. I've tried using Response.OutputStream, Response.WriteFile, and making use of a MemoryStream, among several other things that I've lost track of. I'm hoping there's something simple, maybe some sort of property of the Page or btnPDF I could be missing. Here is the markup for btnPDF, just in case:
<asp:linkButton ID="btnPDF" CssClass="btn btn-default" runat="server" Width="115px">
<i class="fa fa-file-text" title="Edit"></i> PDF
</asp:linkButton>
What could be causing such a problem? Where should I look at this point?
Let me know if more information is needed.
Thanks,
Shane
EDIT:
I experimented with setting a session variable on btnPDF_Click, and handling the PDF download on postback. Again, a valid byte array was generated, but the HttpResponse did not cause the PDF to download from the browser.
EDIT:
Building on the last edit, this tells me that calling DownloadReportPDF from Page_Load works only when IsPostBack is false. I just tested this thought, and it holds true. In the above code, if I check IsPostBack at the moment I'm trying to download the PDF, it is true. Investigating further.
Alright, I finally found a solution I'm satisfied with (though I still don't understand why I can't download the PDF using Response while IsPostBack is true).
Inspired by this thread, I put the previously posted code in an HttpHandler called PDFDownloadHandler, then used Response.Redirect in the btnPDF_Click event handler to utilize PDFDownloadHandler. This article helped me a lot on that process, as it is something I have not done before.
In case anyone else runs into this problem, here is the new PDFDownloadHandler:
Imports Microsoft.VisualBasic
Imports System.Web
Imports Telerik.Reporting
Imports Telerik.Reporting.Processing
Public Class PDFDownloadHandler
Implements IHttpHandler
Public Sub ProcessRequest(ByVal context As _
System.Web.HttpContext) Implements _
System.Web.IHttpHandler.ProcessRequest
Dim request As HttpRequest = context.Request
Dim response As HttpResponse = context.Response
Dim path As String = request.Path
If path.Contains("pps.pdfdownload") Then
Dim releaseMasterId As String = request.QueryString("ID")
If releaseMasterId IsNot Nothing Then
'Service call to generate report source
Dim service As New TelerikReportLibrary.ReportServices.PPSReportService
Dim source As Telerik.Reporting.TypeReportSource = service.GetReportSource(releaseMasterId)
'Render PDF and save
Dim reportProcessor As New ReportProcessor()
Dim result As RenderingResult = reportProcessor.RenderReport("PDF", source, Nothing)
Dim fileName As String = result.DocumentName + "_" + releaseMasterId + "." + result.Extension
response.Clear()
response.ContentType = result.MimeType
response.Cache.SetCacheability(HttpCacheability.Private)
response.Expires = -1
response.Buffer = True
response.AddHeader("Content-Disposition", String.Format("{0};FileName={1}", "attachment", fileName))
response.BinaryWrite(result.DocumentBytes)
End If
End If
response.End()
End Sub
Public ReadOnly Property IsReusable() As Boolean _
Implements System.Web.IHttpHandler.IsReusable
Get
Return False
End Get
End Property
End Class
Any further insight on why the original technique did not work is greatly appreciated.
I'm trying to scrape some schedules off of a website. the information is displayed in a GridView with paging.
The url is:
http://www.landmarkworldwide.com/when-and-where/register/search-results.aspx?prgid=0&pgID=270&crid=0&ctid=&sdt=0
My Issue is when I want to scrape pages other then #1 in the grid view.
The best post I found so far was This One, but it doesn't work and that topic is not complete. I tried to use Fiddler and Chrome to get the post data and use it, but I can't get it to work for me. Can you guys see what's missing?
Here's the code I am using. it's in VB, but you can answer in C# and I'll translate -) (sorry)
Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
Dim lcUrl As String = "http://www.landmarkworldwide.com/when-and-where/register/search-results.aspx?prgid=0&pgID=270&crid=0&ctid=&sdt=0"
' first, request the login form to get the viewstate value
Dim webRequest__1 As HttpWebRequest = TryCast(WebRequest.Create(lcUrl), HttpWebRequest)
Dim responseReader As New StreamReader(webRequest__1.GetResponse().GetResponseStream())
Dim responseData As String = responseReader.ReadToEnd()
responseReader.Close()
' extract the viewstate value and build out POST data
Dim viewState As String = ExtractViewState(responseData)
Dim loHttp As HttpWebRequest = DirectCast(WebRequest.Create(lcUrl), HttpWebRequest)
' *** Send any POST data
Dim lcPostData As String = [String].Format("__VIEWSTATE={0}&__EVENTTARGET={1}&__EVENTARGUMENT={2}", viewState, HttpUtility.UrlEncode("contentwrapper_0$maincontent_0$maincontentfullwidth_0$ucSearchResults$gvPrograms"), HttpUtility.UrlEncode("Page$3"))
loHttp.Method = "POST"
Dim lbPostBuffer As Byte() = System.Text.Encoding.GetEncoding(1252).GetBytes(lcPostData)
loHttp.ContentLength = lbPostBuffer.Length
Dim loPostData As Stream = loHttp.GetRequestStream()
loPostData.Write(lbPostBuffer, 0, lbPostBuffer.Length)
loPostData.Close()
Dim loWebResponse As HttpWebResponse = DirectCast(loHttp.GetResponse(), HttpWebResponse)
Dim enc As Encoding = System.Text.Encoding.GetEncoding(1252)
Dim loResponseStream As New StreamReader(loWebResponse.GetResponseStream(), enc)
Dim lcHtml As String = loResponseStream.ReadToEnd()
loWebResponse.Close()
loResponseStream.Close()
Response.Write(lcHtml)
End Sub
Private Function ExtractViewState(s As String) As String
Dim viewStateNameDelimiter As String = "__VIEWSTATE"
Dim valueDelimiter As String = "value="""
Dim viewStateNamePosition As Integer = s.IndexOf(viewStateNameDelimiter)
Dim viewStateValuePosition As Integer = s.IndexOf(valueDelimiter, viewStateNamePosition)
Dim viewStateStartPosition As Integer = viewStateValuePosition + valueDelimiter.Length
Dim viewStateEndPosition As Integer = s.IndexOf("""", viewStateStartPosition)
Return HttpUtility.UrlEncodeUnicode(s.Substring(viewStateStartPosition, viewStateEndPosition - viewStateStartPosition))
End Function
To make it work you need to send all input fields to the page, not only viewstate. Other critical data is the __EVENTVALIDATION for example that you do not handle it. So:
First you need to make scrape on the #1 page. So load it and use the Html Agility Pack to convert it to a usable struct.
Then extract from that struct the input data that you need to post. From this answer HTML Agility Pack get all input fields here is a code sniped on how you can do that.
foreach (HtmlNode input in doc.DocumentNode.SelectNodes("//input"))
{
// use this to create the post string
// input.Attributes["value"];
}
Then when you have the post data that is needed to be a valid post, you move to the next step. Here is an example How to pass POST parameters to ASP.Net web request?
You can also read: How to use HTML Agility pack
I am using the below code to get the Title and description of the youtube video embeded in my asp.net application. I am able to see the Title, but not description.
I use Atomfeed to do this...
Problem is i get the Description as "Google.GData.Client.AtomTextConstruct" for all my videos.
Private Function GetTitle(ByVal myFeed As AtomFeed) As String
Dim strTitle As String = ""
For Each entry As AtomEntry In myFeed.Entries
strTitle = entry.Title.Text
Next
Return strTitle
End Function
Private Function GetDesc(ByVal myFeed As AtomFeed) As String
Dim strDesc As String = ""
For Each entry As AtomEntry In myFeed.Entries
strDesc = entry.Summary.ToString()
Next
Return strDesc
End Function
I believe that when the XML from the atom feed is parsed, that the description is not handled. Take a look at this: http://code.google.com/p/google-gdata/wiki/UnderstandingTheUnknown
But what happens with things that are not understood? They end up as
an element of the ExtensionElements collection, that is a member of
all classes inherited from AtomBase, like AtomFeed, AtomEntry,
EventEntry etc...
So, what we can do is pull out the description from the extensionelement like this:
Dim query As New FeedQuery()
Dim service As New Service()
query.Uri = New Uri("https://gdata.youtube.com/feeds/api/standardfeeds/top_rated")
Dim myFeed As AtomFeed = service.Query(query)
For Each entry In myFeed.Entries
For Each obj As Object In entry.ExtensionElements
If TypeOf obj Is XmlExtension Then
Dim xel As XElement = XElement.Parse(TryCast(obj, XmlExtension).Node.OuterXml)
If xel.Name = "{http://search.yahoo.com/mrss/}group" Then
Dim descNode = xel.Descendants("{http://search.yahoo.com/mrss/}description").FirstOrDefault()
If descNode IsNot Nothing Then
Console.WriteLine(descNode.Value)
End If
Exit For
End If
End If
Next
Next
Also, the reason why you are getting "Google.GData.Client.AtomTextConstruct" is because Summary is an object of type Google.GData.Client.AtomTextConstruct, so doing entry.Summary.ToString() is just giving you the default ToString() behavior. You would normally do Summary.Text, but this of course is blank because as I say above, it's not handled properly by the library.
For youtube, I fetch the information for each video using the Google.GData.YouTube.
Something like this returns a lot of information from the video.
Dim yv As Google.YouTube.Video
url = New Uri("http://gdata.youtube.com/feeds/api/videos/" & video.Custom)
r = New YouTubeRequest(New YouTubeRequestSettings("??", "??"))
yv = r.Retrieve(Of Video)(url)
Then it's possible to get the description with: yv.Description
I needed to get values out of a string in a QueryString format, that is such as: data1=value1&data2=value2...
Someone suggested I used HttpUtility.ParseQueryString to get the value, I've searched and searched but I can't find any documentation or implementation of this and the Microsoft documentation for it doesn't explain how it works, can someone tell me hwat I'm doing wrong, my code is below;
Public Shared Sub ProcessString(ByVal Vstring As String)
Dim var As NameValueCollection = HttpUtility.ParseQueryString(Vstring)
Dim vname As String = var.QueryString("VNAME")
End Sub
MSDN has an example.
' Parse the query string variables into a NameValueCollection.
Dim qscoll As System.Collections.Specialized.NameValueCollection = HttpUtility.ParseQueryString(Vstring)
Dim vname As String = qscoll("VNAME")
A NameValueCollection represents a collection of associated String keys and String values that can be accessed either with the key or with the index.
I found the problem, I was referencing everything fine but I was doing it in a separate .VB dependency file, once I did it on the actual code behind of the aspx form that solved the problem and it all worked. So now I'm just passing the string from Codebehind as a specialised.NameValue collection in to the function.