If you want to open pdf File in new Tab with clicking hyperlink follow this
1: Add one form as PDFViewer.aspx.
2: on the Page_Load event of this form add following code.
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
Response.ClearHeaders();
Response.ClearContent();
Response.Redirect("nameofPDFFile.pdf");
}
}
3. set properties of hyperlink is follows:
<asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl="~/PDFViewer.aspx"
Target="_blank">HyperLink</asp:HyperLink>