Chrome has a setting that blocks the opening of local files. The specific error you get is Not allowed to load local resource: file:///<file name>. I'm trying to develop an internal site for us to access these files but as many users are using Chrome, I need a workaround to serve these files.
Currently, to get my files and display them, I have this logic:
For Each file As String In Directory.GetFiles("<file path>")
fileInfo = New FileInfo(file)
fileList.Add(fileInfo)
Next
fileList.Sort(Function(x, y) x.Name.CompareTo(y.Name))
For i As Integer = 0 To fileList.Count - 1
pnlLinks.Controls.Add(New LiteralControl("<br />"))
pnlLinks.Controls.Add(New LiteralControl("" & fileList(i).Name & ""))
pnlLinks.Controls.Add(New LiteralControl("          "))
pnlLinks.Controls.Add(New LiteralControl("<span>" & GetByteSize(fileList(i).Length.ToString) & " </span>"))
pnlLinks.Controls.Add(New LiteralControl("<br />"))
Next
The a href is a little funky because I've been experimenting with different folder structures to get this working, but it should not be relevant.
I had the idea of implementing a function that could send this to a byte stream but I'm not experienced in that area and wouldn't be sure how to implement it.
I was able to resolve this with a FileStream and launching to a new page that handles it on Page_Load
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim pdfFileStream As FileStream = Nothing
Dim pdfFileSize As Long = 0
Dim pdfPath As String = "<file path>"
pdfFileStream = New FileStream(pdfPath, FileMode.Open)
pdfFileSize = pdfFileStream.Length
Dim Buffer(CInt(pdfFileSize)) As Byte
pdfFileStream.Read(Buffer, 0, CInt(pdfFileSize))
pdfFileStream.Close()
Response.ContentType = "application/pdf"
Response.OutputStream.Write(Buffer, 0, pdfFileSize)
Response.Flush()
Response.Close()
End Sub
Related
I'm trying to generate a PDF using Winnovative Tools. In my click handler which fires after clicking on the "Print PDF button", I have the code below.
I expect control to resume to the printPDF_Click sub routine after calling Server.Execute() but instead it calls the printPDF_Click sub routine from scratch which causes a loop because Server.Execute() will be called again and so on.
It works as expected when I set preserveForm as False but then I lose my form data and the point is retaining it.
Private Sub printPDF_Click(sender As Object, e As EventArgs) Handles printPDF.Click
Dim outTextWriter As IO.TextWriter = New IO.StringWriter()
Server.Execute("Default_v3.aspx?isWinnovative=true", outTextWriter)
Dim baseUrl As String = HttpContext.Current.Request.Url.AbsoluteUri
Dim htmlStringToConvert As String = outTextWriter.ToString()
Dim downloadBytes As Byte() = PdfHelper.CreatePdf(htmlStringToConvert, baseUrl)
Dim response As HttpResponse = HttpContext.Current.Response
response.Clear()
response.AddHeader("Content-Type", "binary/octet-stream")
response.AddHeader("Content-Disposition", ("attachment; filename=" + (
"Rendered.pdf" + ("; size=" + downloadBytes.Length.ToString))))
response.Flush()
response.BinaryWrite(downloadBytes)
response.Flush()
response.End()
End Sub
I am trying to create a simple encryption program with visual basic on visual studio. My program is to encrypt an image then decrypt it. The system is saying that the request is not supported. As a note I am just learning about encrypting and not sure if I am even doing this correctly. Any comments or help would be much appreciated.
Error is from this: File.Encrypt(FileName)
if my encrypt is creating an error then my decrypt will most likely as well
Imports System
Imports System.IO
Imports System.Security.Cryptography
Partial Class _Default
Inherits System.Web.UI.Page
'My Encrypt button that takes the file from my FileUpload tool and Encrypts it, then outputs on my label
'that the file was successfully encrypted
Protected Sub EncryptButton_Click(sender As Object, e As EventArgs) Handles EncryptButton.Click
Dim FileName As String = FileUpload1.FileName
File.Encrypt(FileName)
Label1.Text = "Encrypt" + FileName
End Sub
'My Decrypt button that takes the file from my FileUpload tool and Encrypts it, then outputs on my label
'that the file was successfully encrypted
Protected Sub DecryptButton_Click(sender As Object, e As EventArgs) Handles DecryptButton.Click
Dim FileName As String = FileUpload1.FileName
File.Decrypt(FileName)
Label1.Text = "Decrypt" + FileName
End Sub
'Load page that will display a success output on the label if the upload is completed
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
If FileUpload1.HasFile = True Then
Label1.Text = "Success"
Else
Label1.Text = "Failed"
End If
End Sub
Protected Sub CustomValidator1_ServerValidate(source As Object, args As ServerValidateEventArgs) Handles CustomValidator1.ServerValidate
'Verify the control has a file
If Not FileUpload1.HasFile Then
CustomValidator1.ErrorMessage = "A file is required in order to proceed"
args.IsValid = False
Else
'next 2 lines are all one line
Dim ext As String =
System.Web.VirtualPathUtility.GetExtension(FileUpload1.FileName).ToUpper()
If Not ext = ".GIF" And Not ext = ".JPG" And Not ext = ".PNG" Then
'next 2 lines are all one line
CustomValidator1.ErrorMessage = String.Concat("Invalid file type '", ext, "' -must be .gif or .jpg or .png to continue")
args.IsValid = False
Else
args.IsValid = True
End If
End If
End Sub
End Class
I searched for "System.IO.IOException" and found Troubleshooting Exceptions: System.IO.IOException which states
Make sure the file and directory exist.
Then looking at the code:
Dim FileName As String = FileUpload1.FileName
I see that there is no directory specified for the file. So, you need to use Path.Combine so that you can give File.Encrypt the full filename including the path.
(There is no indiction in the posted code of which directory the uploaded file is in, so I can't help further with that. It could be that FileUpload1 has a property which gives that.)
The following code is my current attempt at opening some data in excel from a website button in VB.Net. I would like the data to show up barebones, but the formatting from the table on the website always follows. The paging and colors make the data near impossible to read and can only see the first page of data. Any quick fixes? I've tried a lot of things I've found on here but to no avail.
Private Sub DownloadExcel()
Response.Clear()
'Dim dt As DataTable = TryCast(ViewState("GridData"), DataTable)
Grid_Bad_Meters.AllowPaging = False
Grid_Bad_Meters.AllowSorting = False
'Grid_Bad_Meters.DataSource = dt
'Grid_Bad_Meters.DataBind()
Dim sfile As String = "Communication_Failures" & Now.Ticks
Response.AddHeader("content-disposition", "attachment;filename=" & sfile & ".xls")
Response.Charset = ""
' If you want the option to open the Excel file without saving then
' comment out the line below
' Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.ContentType = "application/vnd.ms-excel"
Dim stringWrite As New System.IO.StringWriter()
Dim htmlWrite As System.Web.UI.HtmlTextWriter = New HtmlTextWriter(stringWrite)
Grid_Bad_Meters.RenderControl(htmlWrite)
Response.Write(stringWrite.ToString())
Response.End()
'Grid_Bad_Meters.AllowPaging = True
'Grid_Bad_Meters.AllowSorting = True
'GridView1.DataSource = dt
'GridView1.DataBind()
End Sub
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Try
Dim ScriptManager As ScriptManager = ScriptManager.GetCurrent(Me.Page)
ScriptManager.RegisterPostBackControl(Me.btnExportToExcel)
Catch ex As Exception
End Try
End Sub
Protected Sub btnExportToExcel_Click(sender As Object, e As EventArgs) Handles btnExportToExcel.Click
Try
Dim sw As New System.IO.StringWriter()
Dim hw As New System.Web.UI.HtmlTextWriter(sw)
Dim style As String = "<style>.textmode{mso-number-format:\#;}</style>"
Response.Clear()
Response.Buffer = True
Response.AddHeader("content-disposition", "attachment;filename=SignExport.xls")
Response.Charset = ""
Response.ContentType = "application/vnd.ms-excel"
For i As Integer = 0 To Me.Grid_Bad_Meters.Rows.Count - 1
Dim row As GridViewRow = Grid_Bad_Meters.Rows(i)
row.Attributes.Add("class", "textmode")
Next
'lblRptHeader.RenderControl(hw)
hw.WriteBreak()
'lblReportDateRange.RenderControl(hw)
Grid_Bad_Meters.RenderControl(hw)
Response.Write(style)
Response.Output.Write(sw.ToString())
Response.Flush()
Response.End()
Catch ex As Exception
End Try
End Sub
You could use one of the two approaches mentioned below. Of course, there are other ways of meeting your requirement like exporting to csv file as mentioned in a comment or using a .Net library meant for Excel exporting like epplus.
OpenXML Approach
If you are looking for a way to export to Excel without using the html approach, then you can use OpenXML approach that is explained very clearly with a working example at this URL: Export to Excel using OpenXML. This will eliminate all the CSS styles that can get associated with exporting using html approach and you seem to be using this html approach according to the code in your original post. However, if you want to use the html approach, then the code below should work and eliminate all CSS styles that can come in the way when viewing the excel file. I have actually tried this posted code on my machine before putting it here.
Html Approach
You can create a new instance of GridView in your export method rather than use an existing instance, and data bind it to same data as the existing gridview on your page before rendering it to excel. Before you data bind it in the export method you need to make sure that no styles are set and specifically the grid line are set to none as in code below.
You can see an actual video of how this works at this URL : Grid Export without any CSS Styles. This was how the code behaved on my laptop when I ran it.
You can use sample code below, but make sure the data source is set to data that includes all records across all pages of original gridview. I have used SqlDataSource1 as data source but you can replace it by an appropriate method in your situation.
Protected Sub btnExport_Click(sender As Object, e As EventArgs)
Dim GridView2 As New GridView()
GridView2.AllowPaging = False
GridView2.AllowSorting = False
GridView2.Style.Clear()
GridView2.CellPadding = 0
GridView2.CellSpacing = 0
GridView2.GridLines = GridLines.None
GridView2.BorderStyle = BorderStyle.None
GridView2.BorderWidth = Unit.Pixel(0)
GridView2.AlternatingRowStyle.BorderStyle = BorderStyle.None
GridView2.DataSource = SqlDataSource1
GridView2.DataBind()
' Clear the response
Response.Clear()
' Set the type and filename
Response.AddHeader("content-disposition", "attachment;filename=griddata.xls")
Response.Charset = ""
Response.ContentType = "application/vnd.xls"
' Add the HTML from the GridView to a StringWriter so we can write it out later
Dim sw As New System.IO.StringWriter()
Dim hw As System.Web.UI.HtmlTextWriter = New HtmlTextWriter(sw)
GridView2.RenderControl(hw)
' Write out the data
Response.Write(sw.ToString())
Response.[End]()
End Sub
Public Overrides Property EnableEventValidation() As Boolean
Get
Return False
End Get
'Do nothing
Set
End Set
End Property
Public Overrides Sub VerifyRenderingInServerForm(control As Control)
'Allows for printing
End Sub
I'm trying to restrict anonymous users from browsing directly to a particular filename (image file) in a folder on my website. But when I turn on the "IIS Authentication" feature on the folder, both anonymous users and the website application can't access the image file.
How can I deny access to the file for anonymous users (for example, if the user were to type in the absolute url), but allow access to the website application? (I thought that maybe the "IP Address and Domain Restrictions" feature could be used, as well, but couldn't get it to work)
I could move the image file to a folder outside of the website, but then not sure how to use it in the .ImageUrl property.
...bump
EDIT - Solution (put following in a .aspx page and set the ImageUrl property to this page, with any needed querystring parameters):
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If (Request.QueryString("FileType") IsNot Nothing) And (Request.QueryString("FileName") IsNot Nothing) Then
Try
' Read the file and convert it to Byte Array
Dim filePath As String = UrlXlat(Request.QueryString("FileType") & "\")
Dim fileName As String = Request.QueryString("FileName")
Dim contentType As String = "image/" & Path.GetExtension(fileName).Replace(".", "")
Dim fs As FileStream = New FileStream(filePath & fileName, FileMode.Open, FileAccess.Read)
Dim br As BinaryReader = New BinaryReader(fs)
Dim bytes As Byte() = br.ReadBytes(Convert.ToInt32(fs.Length))
br.Close()
fs.Close()
'Write the file to Reponse
Response.Buffer = True
Response.Charset = ""
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.ContentType = contentType
Response.AddHeader("content-disposition", "attachment;filename=" & fileName)
Response.BinaryWrite(bytes)
Response.Flush()
Response.End()
Catch ex As Exception
response.write(ex):response.end
End Try
End If
End Sub
You can move the file either to a folder outside of the root of the site or to the App_Data folder (which is protected form direct browsing by the ASP.NET framework) and then set your ImageUrl to point to a generic handler (.ashx file) which will be responsible for delivering the file to the browser. You perform your authentication checks in the handler.
I've written an article that provides implementation details: http://www.mikesdotnetting.com/article/122/simple-file-download-protection-with-asp-net
I'm currently trying to open a PDF file on my website that is located on my company's network. I had this working previously, but now for some reason it isn't working. Here is what I have:
I am using impersonation to access the file. It has domain admin privileges. This is from my web.config file (username/password are altered):
<identity impersonate="true" password="pass" userName="domain\user" />
I use this code to open the PDF in a window:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Try
Dim strPath As String = CStr(Session("DWGPath"))
strPath = "file://san01/prodeng/" + Mid(strPath, 4)
strPath = Replace(strPath, "\", "/")
Dim pdfPath As String = strPath
Dim client As WebClient = New WebClient()
Dim buffer As Byte() = client.DownloadData(pdfPath)
Response.ContentType = "application/pdf"
Response.AddHeader("content-length", buffer.Length.ToString())
Response.BinaryWrite(buffer)
Response.End()
Catch exa As WebException
Response.Redirect("DrawingError.aspx")
Catch ex As Exception
Throw ex
End Try
End Sub
This doesn't work. It redirects me to the "DrawingError.aspx" page. This link dispalys the "Session("DWGPath")" variable. I can take this variable and paste it in to my browser and the PDF opens without problem.
However, if I alter my code to this:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Try
Dim strPath As String = CStr(Session("DWGPath"))
Dim pdfPath As String = strPath
Dim client As WebClient = New WebClient()
Dim buffer As Byte() = client.DownloadData(pdfPath)
Response.ContentType = "application/pdf"
Response.AddHeader("content-length", buffer.Length.ToString())
Response.BinaryWrite(buffer)
Response.End()
Catch exa As WebException
Response.Redirect("DrawingError.aspx")
Catch ex As Exception
Throw ex
End Try
End Sub
It still doesn't work.
The account also has full control privileges to the folder that contains the PDFs.
Any help or insight would be appreciated. Thank you!
EDIT: IF I throw exa then I get this:
The account used is a computer account. Use your global user account or local user account to access this server.
I assume you're running IIS. Go to the application pool for this app and change the identity that it's running under to be the domain\user account. See if that fixes your problem.
You want to make sure that the password on this account doesn't change or else it will fail when the password expires.