VB导出页面为PDF

Question

我正在尝试将aspx页面转换为PDF。输出文件很奇怪（包括css脚本）

背后的代码

Imports iTextSharp.text
Imports System.IO
Imports iTextSharp.text.html.simpleparser
Imports iTextSharp.text.pdf

    Protected Sub btnExport_Click(sender As Object, e As EventArgs)
        Response.ContentType = "application/pdf"
        Response.AddHeader("content-disposition", "attachment;filename=TestPage.pdf")
        Response.Cache.SetCacheability(HttpCacheability.NoCache)
        Dim sw As New StringWriter()
        Dim hw As New HtmlTextWriter(sw)
        Me.Page.RenderControl(hw)
        Dim sr As New StringReader(sw.ToString())
        Dim pdfDoc As New Document(PageSize.A4, 10.0F, 10.0F, 100.0F, 0.0F)
        Dim htmlparser As New HTMLWorker(pdfDoc)
        PdfWriter.GetInstance(pdfDoc, Response.OutputStream)
        pdfDoc.Open()
        htmlparser.Parse(sr)
        pdfDoc.Close()
        Response.Write(pdfDoc)
        Response.[End]()
    End Sub

如何从输出文件和表格式中删除css是不合适的，原始网页输出是