浏览到 ASP.NET Web 站点文件夹中的 PDF

Question

I have an ASP.NET Core web site running under IIS on a server. I created a folder and want to display any pdf file in that folder in the browser using the url for the site.

https://example.com/pdf/myfile.pdf

folder structure: c:\inetpub\wwwroot\mysite\pdf\myfile.pdf - contains pdf files

I enabled Directory Browsing for the site in IIS Manager, but I get a 404 error. I'm on Window Server 2019 IIS version 10.

Answer 1

I would dispense with folder/directory browsing. You can't control the user experince and UI.

And it just we few lines of code to display the files in a web page, and then have a button to display the pdf in the browser.

So our markup is like this:

       <h2>Select a PDF file to view</h2>
        <br />

        <div style="width:45%">
        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" CssClass="table table-hover">
            <Columns>
                <asp:BoundField DataField="Date" HeaderText="Date" ItemStyle-Width="100px" />
                <asp:BoundField DataField="File Name" HeaderText="ID" />
                <asp:BoundField DataField="File Size" HeaderText="Size" ItemStyle-Width="100px" />

                <asp:TemplateField>
                    <ItemTemplate>
                        <asp:Button ID="cmdDownLoad" runat="server" Text="View" 
                            OnClick="cmdDownLoad_Click" 
                            Row = '<%# Container.DataItemIndex %>'/>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
        </div>

And our code to pull files from a folder and shove into the above gridview looks like this:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    If IsPostBack = False Then

        ShowFiles()

    End If

End Sub

Sub ShowFiles()
    Dim MyTable As New DataTable

    MyTable.Columns.Add("Date", GetType(String))
    MyTable.Columns.Add("File Size", GetType(String))
    MyTable.Columns.Add("File Name", GetType(String))
    MyTable.Columns.Add("FullFile", GetType(String))

    'Dim strFolder = Server.MapPath("/app_data")
    Dim strFolder = "c:\Test4"
    Dim MyDir As New DirectoryInfo(strFolder)

    Dim MyFiles() As FileInfo = MyDir.GetFiles("*.pdf")

    For Each MyFile As FileInfo In MyFiles
        Dim oneRow As DataRow = MyTable.Rows.Add

        oneRow("Date") = MyFile.LastAccessTime.ToShortDateString
        oneRow("File Size") = Int(MyFile.Length / 1024) & " KB"
        oneRow("File Name") = MyFile.Name
        oneRow("FullFile") = MyFile.FullName

    Next

    ViewState("MyTable") = MyTable

    GridView1.DataSource = MyTable
    GridView1.DataBind()

End Sub

The result is thus this:

So, now all we need is the button code to display the pdf in the browser.

This will work:

Protected Sub cmdDownLoad_Click(sender As Object, e As EventArgs)

    Dim btn As Button = sender

    Dim RowID = btn.Attributes.Item("Row")
    Dim MyTable As DataTable = ViewState("MyTable")

    With MyTable.Rows(RowID)
        ShowPdf(.Item("File Name"), .Item("FullFile"))
    End With

End Sub

Sub ShowPdf(strFileOnlyName As String, strFile As String)

    Dim pDFData As Byte()
    pDFData = File.ReadAllBytes(strFile)

    Response.Buffer = False     ' //transmitfile self buffers
    Response.Clear()
    Response.ClearContent()
    Response.ClearHeaders()

    Response.AddHeader("Accept-Header", pDFData.Length.ToString())
    Response.AddHeader("Content-Length", pDFData.Length.ToString())

    Response.AddHeader("Content-Disposition", "inline; filename=" & strFileOnlyName)

    Response.AddHeader("Expires", "0")
    Response.AddHeader("Cache-Control", "private")
    Response.ContentType = "application/pdf"
    Response.AddHeader("Accept-Ranges", "bytes")
    Response.BinaryWrite(pDFData)
    Response.Flush()
    Response.End()

End Sub

So you can click on the button - it will display the PDF in the browser. If you hit back, then you back to the grid, and you can then view another file.