how to open pdf file in browser in new tab

Hi manishpand,

I have created sample code which fullfill requirement

HTML

  <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
            <Columns>
                <asp:BoundField DataField="Name" HeaderText="File Name" />
                <asp:TemplateField ItemStyle-HorizontalAlign="Center">
                    <ItemTemplate>
                        <asp:LinkButton ID="lnkView" runat="server" Text="View" OnClick="View" CommandArgument='<%# Eval("Id") %>'></asp:LinkButton>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>

C#

 private void BindGrid()
    {
        string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand())
            {
                cmd.CommandText = "SELECT Id, Name FROM tblFiles";
                cmd.Connection = con;
                con.Open();
                GridView1.DataSource = cmd.ExecuteReader();
                GridView1.DataBind();
                con.Close();
            }
        }
    }
 protected void View(object sender, EventArgs e)
    {
        string url = string.Format("Default.aspx?Id={0}", (sender as LinkButton).CommandArgument);
        string script = "<script type='text/javascript'>window.open('" + url + "')</script>";
        this.ClientScript.RegisterStartupScript(this.GetType(), "script", script);
    }

Second Page:

HTML

        <div>
            <asp:Literal ID="ltEmbed" runat="server" />
        </div>

C#

protected void Page_Load(object sender, EventArgs e)
{
    string embed = "<object data=\"{0}{1}\" type=\"application/pdf\" width=\"500px\" height=\"300px\">";
    embed += "If you are unable to view file, you can download from <a href = \"{0}{1}&download=1\">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("~/FileCS.ashx?Id="), Request.QueryString["Id"]);
 }

Add Handler

public void ProcessRequest(HttpContext context)
{
    int id = int.Parse(context.Request.QueryString["Id"]);
    byte[] bytes;
    string fileName, contentType;
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand())
        {
            cmd.CommandText = "SELECT Name, Data, ContentType FROM tblFiles WHERE Id=@Id";
            cmd.Parameters.AddWithValue("@Id", id);
            cmd.Connection = con;
            con.Open();
            using (SqlDataReader sdr = cmd.ExecuteReader())
            {
                sdr.Read();
                bytes = (byte[])sdr["Data"];
                contentType = sdr["ContentType"].ToString();
                fileName = sdr["Name"].ToString();
            }
            con.Close();
        }
    }

    context.Response.Buffer = true;
    context.Response.Charset = "";
    if (context.Request.QueryString["download"] == "1")
    {
        context.Response.AppendHeader("Content-Disposition", "attachment; filename=" + fileName);
    }
    context.Response.Cache.SetCacheability(HttpCacheability.NoCache);
    context.Response.ContentType = "application/pdf";
    context.Response.BinaryWrite(bytes);
    context.Response.Flush();
    context.Response.End();
}

public bool IsReusable
{
    get
    {
        return false;
    }
}

I hope help you.