How to Convert PDF to PNG in ASP.NET?

using System;
using System.Web.UI;
using System.IO;
using PQScan.PDFToImage;

public partial class _Default: System.Web.UI.Page
{
  protected void Page_Load(object sender, EventArgs e)
  {
    // Prepare a PDF file.
    string pdfFileName = Server.MapPath("sample.pdf");

    // Create an instance of PQScan.PDFToImage.PDFDocument object.
    PDFDocument pdfDoc = new PDFDocument();

    // Load the PDF file.
    pdfDoc.LoadPDF(pdfFileName);

    // Prepare response.
    Response.Clear();
    Response.ContentType = "image/png";

    // Render the first page of PDF file to the output image.
    System.Drawing.Image pngImage = pdfDoc.ToImage(0);

    using (MemoryStream ms = new MemoryStream())
    {
      // Save image to png format.
      pngImage.Save(ms, System.Drawing.Imaging.ImageFormat.Png);

      // Display png image to the aspx web page.
      Response.OutputStream.Write(ms.GetBuffer(), 0, (int)ms.Length);
    }

    pngImage.Dispose();

    Response.End();
  }
}

Imports System
Imports System.Web.UI
Imports System.IO
Imports PQScan.PDFToImage

Public partial Class _Default
     Inherits System.Web.UI.Page
  Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    ' Prepare a PDF file.
    Dim pdfFileName As String = Server.MapPath("sample.pdf")

    ' Create an instance of PQScan.PDFToImage.PDFDocument object.
    Dim pdfDoc As PDFDocument = New PDFDocument()

    ' Load the PDF file.
    pdfDoc.LoadPDF(pdfFileName)

    ' Prepare response.
    Response.Clear()
    Response.ContentType = "image/png"

    ' Change the first page of PDF file to the output image.
    Dim pngImage As System.Drawing.Image = pdfDoc.ToImage(0)

    Imports (MemoryStream ms = New MemoryStream())
    {
      ' Save image to png file format.
      pngImage.Save(ms, System.Drawing.Imaging.ImageFormat.Png)

      ' Show png image to your ASP.NET web page.
      Response.OutputStream.Write(ms.GetBuffer(), 0, CType(ms.Length, Integer))
    }

    pngImage.Dispose()

    Response.End()
  End Sub
End Class