Open PDF File in New Window or New Tab on Button click in ASP.Net

Hi,

you can set file name in command argument of link button.

Try the following sample to understand.

HTML

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

Code

C#

Default

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        string[] filePaths = Directory.GetFiles(Server.MapPath("~/Reports/"));
        List<ListItem> files = new List<ListItem>();
        foreach (string filePath in filePaths)
        {
            files.Add(new ListItem(Path.GetFileName(filePath), filePath));
        }
        GridView1.DataSource = files;
        GridView1.DataBind();
    }
}

protected void ViewFile(object sender, EventArgs e)
{
    string url = string.Format("Home.aspx?FN={0}", (sender as LinkButton).CommandArgument);
    string script = "<script type='text/javascript'>window.open('" + url + "')</script>";
    this.ClientScript.RegisterStartupScript(this.GetType(), "script", script);
}

Home

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        string filePath = Server.MapPath("~/Reports/") + Request.QueryString["FN"];
        this.Response.ContentType = "application/pdf";
        this.Response.AppendHeader("Content-Disposition;", "attachment;filename=" + Request.QueryString["FN"]);
        this.Response.WriteFile(filePath);
        this.Response.End();
    }
}

VB.Net

Default

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim filePaths As String() = Directory.GetFiles(Server.MapPath("~/Reports/"))
        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 url As String = String.Format("Home.aspx?FN={0}", (TryCast(sender, LinkButton)).CommandArgument)
    Dim script As String = "<script type='text/javascript'>window.open('" & url & "')</script>"
    Me.ClientScript.RegisterStartupScript(Me.GetType(), "script", script)
End Sub

Home

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim filePath As String = Server.MapPath("~/Reports/") + Request.QueryString("FN")
        Me.Response.ContentType = "application/pdf"
        Me.Response.AppendHeader("Content-Disposition;", "attachment;filename=" & Request.QueryString("FN"))
        Me.Response.WriteFile(filePath)
        Me.Response.[End]()
    End If
End Sub

Screenshot

This is just sample for your problem.

1.First fetch desired file name.and send it to the next page by querystring.

2.Construct the file path as i did in sample .

3.then write file in response stream to display.

4.This will provide functionality to display pdf on new window

use same sample and download file using datakey instead of CommandArgument