illegal charcters in path when viewer files in browser

Question

User-289010069 posted

I'm trying to display files in a browser window when a gridview linkbutton is clicked on RowCommand.  Whenever I try to display a file, I receive an illegal character in path error message.  I'm sure it has something to do with the characters in the sample file path below.   Can someone offer any advice on how to resolve the issue?

ex. file path format - \\directory1\directory2\232-3434-34354-4334.TestFile.txt

Gridview

   <asp:GridView ID="DocGrid"   runat="server" CssClass="table table-striped table-hover   "
                                    AutoGenerateColumns="False" >
                                    <Columns>
                                        <asp:TemplateField>
                                                <ItemTemplate>
                                                    <asp:LinkButton id="lbView" runat="server" CommandName="ViewDoc"  Text="View Document" CommandArgument="<%# CType(Container,GridViewRow).RowIndex %>">
                                                    
                                                    </asp:LinkButton>
                                                </ItemTemplate> 
                                        </asp:TemplateField> 
                                        <asp:BoundField DataField="doc_id" HeaderText="Doc ID" />
                                        <asp:BoundField DataField="Description" HeaderText="Description" />
                                     
                                    </Columns>
                                </asp:GridView>




 Private Sub DocGrid_RowCommand(sender As Object, e As System.Web.UI.WebControls.GridViewCommandEventArgs) Handles DocGrid.RowCommand

        Dim dsDocs As New DataSet
        Dim drDoc As DataRow = Nothing

        If e.CommandName = "ViewDoc" Then
        
            Dim index As Integer = Convert.ToInt32(e.CommandArgument)
            Dim row As GridViewRow = DocGrid.Rows(index)

            If row IsNot Nothing Then
                
                Try
                   
                    If  dsDocs.Tables(0).Rows.Count > 0 Then
                        drDoc = dsDocs.Tables(0).Rows(0)
                        Dim lbViewDoc As LinkButton = row.FindControl("lbView")
                        Dim path As String = drDoc("FilePath")
                          Dim FileScript As String = "<script language='javascript'>window.open('" + path + "','TestFile');</script>"
                         Page.RegisterStartupScript("open window", FileScript)
                    End If

                Catch ex As Exception
                 
                End Try

            End If
        End If
    End Sub

Answer 1

User475983607 posted

The design will not work because the link is trying to access local resources which violates browser security.

Answer 2

User-289010069 posted

Is there any way to view a file in a pop up window from a linkbutton in the gridview row command event?

Answer 3

User475983607 posted

Is there any way to view a file in a pop up window from a linkbutton in the gridview row command event?

Use the URL of the text file.  If the file is outside the hosted application then write an HTTP Handler to return the file.  The URL is the HTTP Handler where the file is a parameter.

https://www.dotnetperls.com/ashx

https://stackoverflow.com/questions/12087040/file-download-by-calling-ashx-page

http://www.intstrings.com/ramivemula/articles/how-to-download-files-from-server-to-client-using-a-generic-handler/

Answer 4

User288213138 posted

Hi HelloWrold18,

HelloWorld18

Is there any way to view a file in a pop up window from a linkbutton in the gridview row command event?

Due to security issues, the browser cannot open local file, if you want to open the local file in asp.net, you can try below code:

<asp:LinkButton ID="lnkView" runat="server" Text="View File" OnClick="View"></asp:LinkButton>
<hr />
<asp:Literal ID="ltEmbed" runat="server" />
protected void View(object sender, EventArgs e)
{
    string embed = "<object data=\"{0}\" type=\"application/pdf\" width=\"500px\" height=\"300px\">";
    embed += "If you are unable to view file, you can download from <a href = \"{0}\">here</a>";
    embed += " or download <a target = \"_blank\" href = \"http://get.adobe.com/reader/\">Adobe PDF Reader</a> to view the file.";
    embed += "</object>";
    ltEmbed.Text = string.Format(embed, ResolveUrl("~/Files/test.pdf"));  
}

More information about how to open a file you can refer to this link:

https://www.aspsnippets.com/Articles/Open-Show-PDF-File-from-Server-in-ASPNet.aspx

Best regards,

Sam

Answer 5

User-289010069 posted

Thanks for the example but I need a way to open different types of files(excel, word, pdf, txt, etc..) in the browser from the Row Command button click event.  The example is for pdf files. 

Answer 6

User475983607 posted

HelloWorld18

Thanks for the example but I need a way to open different types of files(excel, word, pdf, txt, etc..) in the browser from the Row Command button click event.  The example is for pdf files. 

What is stopping you from updating the code to suite your needs?  Keep in mind, opening a document in a browser window requires browser support.  PDF, Word, and Excel require a browser plugin.   Most browser support PDF but not Word and Excel.

Answer 7

User288213138 posted

Hi HelloWrold18,

Thanks for the example but I need a way to open different types of files(excel, word, pdf, txt, etc..) in the browser from the Row Command button click event.  The example is for pdf files. 

You can try below code, for some browser reasons, I suggest you download the file and then go to view.

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" EmptyDataText="No files uploaded">
                <Columns>
                    <asp:BoundField DataField="Text" HeaderText="FileName" />
                    <asp:TemplateField HeaderText="View">
                        <ItemTemplate>
                            <asp:LinkButton ID="lbView" Text="View" CommandArgument='<%# Eval("Value") %>' runat="server" OnClick="ViewFile"></asp:LinkButton>
                        </ItemTemplate>
                    </asp:TemplateField>     
                </Columns>
            </asp:GridView>

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
        If Not IsPostBack Then
            Dim filePaths As String() = Directory.GetFiles(Server.MapPath("~/Files/"))
            Dim files As List(Of ListItem) = New List(Of ListItem)()

            For Each filePath As String In filePaths
                files.Add(New ListItem(Path.GetFileName(filePath), filePath))
            Next

            GridView1.DataSource = files
            GridView1.DataBind()
        End If
    End Sub

    Protected Sub ViewFile(ByVal sender As Object, ByVal e As EventArgs)
        Dim filePath As String = (TryCast(sender, LinkButton)).CommandArgument
        Response.ContentType = ContentType
        Response.AppendHeader("Content-Disposition", "attachment; filename=" & Path.GetFileName(filePath))
        Response.WriteFile(filePath)
        Response.[End]()
    End Sub

Best regards,

Sam