private void convertToPdfButton_Click(object sender, EventArgs e)
{
    // Create a HTML to PDF converter object with default settings
    HtmlToPdfConverter htmlToPdfConverter = new HtmlToPdfConverter();

    // Set license key received after purchase to use the converter in licensed mode
    // Leave it not set to use the converter in demo mode
    htmlToPdfConverter.LicenseKey = "fvDh8eDx4fHg4P/h8eLg/+Dj/+jo6Og=";

    // Set an adddional delay in seconds to wait for JavaScript or AJAX calls after page load completed
    // Set this property to 0 if you don't need to wait for such asynchcronous operations to finish
    htmlToPdfConverter.ConversionDelay = 2;
            
    // Set proxy type
    // when converting HTML pages from HTTP addresses use the Http proxy type
    // when converting HTML pages from HTTPS addresses use Socks5 proxy type and make sure the proxy server
    // is also configured to use SOCKS5 protocol
    htmlToPdfConverter.ProxyOptions.Type = SelectedProxyType();

    // Set proxy hostname and port number
    // Hostname and port number are required when the proxy type is set to something different from None value
    htmlToPdfConverter.ProxyOptions.HostName = hostNameTextBox.Text;
    htmlToPdfConverter.ProxyOptions.PortNumber = int.Parse(portNumberTextBox.Text);

    // Optionally set proxy username and password if they are required by proxy server
    htmlToPdfConverter.ProxyOptions.Username = usernameTextBox.Text;
    htmlToPdfConverter.ProxyOptions.Password = passwordTextBox.Text;

    // Optionally set a list of hosts to be accessed directly without a proxy
    if (bypassedHostTextBox.Text.Length > 0)
        htmlToPdfConverter.ProxyOptions.BypassedHosts = new string[] { bypassedHostTextBox.Text };

    Cursor = Cursors.WaitCursor;

    // Convert HTML to PDF using the settings above
    string outPdfFile = @"DemoAppFiles\Output\HTML_to_PDF\Proxy_Options.pdf";
    try
    {
        // Convert the HTML page to a PDF document in a memory buffer
        byte[] outPdfBuffer = htmlToPdfConverter.ConvertUrl(urlTextBox.Text);

        // Write the memory buffer in a PDF file
        System.IO.File.WriteAllBytes(outPdfFile, outPdfBuffer);
    }
    catch (Exception ex)
    {
        // The HTML to PDF conversion failed
        MessageBox.Show(String.Format("HTML to PDF Error. {0}", ex.Message));
        return;
    }
    finally
    {
        Cursor = Cursors.Arrow;
    }

    // Open the created PDF document in default PDF viewer
    try
    {
        System.Diagnostics.Process.Start(outPdfFile);
    }
    catch (Exception ex)
    {
        MessageBox.Show(String.Format("Cannot open created PDF file '{0}'. {1}", outPdfFile, ex.Message));
    }
}