EVO HTML to PDF Converter

Execute Acrobat JavaScript Code when a Button is Clicked

EVO HTML to PDF Converter for .NET Documentation

EVO HTML to PDF Converter allows you to add an Acrobat JavaScript code in generated PDF to be executed when a button of a PDF form is clicked. You can set button actions in the generated PDF document to display an alert message, automatically open the print dialog or set the zoom level of the generated PDF document.

An Acrobat JavaScript action is represented by a PdfActionJavaScript object which can be assigned to PdfFormFieldAction property of a PDF form button.

Code Sample - Execute Acrobat JavaScript Code when a Button is Clicked
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protected 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 = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c=";

    // 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;

    Document pdfDocument = null;
    try
    {
        string htmlWithButton = htmlStringTextBox.Text;
        string baseUrl = baseUrlTextBox.Text;

        // Convert a HTML string with a button to a PDF document object
        pdfDocument = htmlToPdfConverter.ConvertHtmlToPdfDocumentObject(htmlWithButton, baseUrl);

        // Get the button location in PDF
        HtmlElementMapping buttonMapping = htmlToPdfConverter.HtmlElementsMappingOptions.HtmlElementsMappingResult.GetElementByMappingId("javascript_button");
        if (buttonMapping != null)
        {
            PdfPage buttonPdfPage = buttonMapping.PdfRectangles[0].PdfPage;
            RectangleF buttonRectangle = buttonMapping.PdfRectangles[0].Rectangle;

            // The font used for buttons text in PDF document
            PdfFont buttonTextFont = pdfDocument.AddFont(new Font("Times New Roman", 8, FontStyle.Regular, GraphicsUnit.Point));

            // Create a PDF form button
            PdfFormButton pdfButton = pdfDocument.Form.AddButton(buttonPdfPage, buttonRectangle, "Execute Acrobat JavaScript", buttonTextFont);

            // Set JavaScript action to be executed when the button is clicked
            string javaScript = null;
            if (alertMessageRadioButton.Checked)
            {
                // JavaScript to display an alert mesage 
                javaScript = String.Format("app.alert(\"{0}\")", alertMessageTextBox.Text);
            }
            else if (printDialogRadioButton.Checked)
            {
                // JavaScript to open the print dialog
                javaScript = "print()";
            }
            else if (zoomLevelRadioButton.Checked)
            {
                // JavaScript to set an initial zoom level 
                javaScript = String.Format("zoom={0}", int.Parse(zoomLevelTextBox.Text));
            }

            // Set the JavaScript action
            pdfButton.Action = new PdfActionJavaScript(javaScript);
        }

        // Save the PDF document in a memory buffer
        byte[] outPdfBuffer = pdfDocument.Save();

        // Send the PDF as response to browser

        // Set response content type
        Response.AddHeader("Content-Type", "application/pdf");

        // Instruct the browser to open the PDF file as an attachment or inline
        Response.AddHeader("Content-Disposition", String.Format("attachment; filename=Button_JavaScript_Actions.pdf; size={0}", outPdfBuffer.Length.ToString()));

        // Write the PDF document buffer to HTTP response
        Response.BinaryWrite(outPdfBuffer);

        // End the HTTP response and stop the current page processing
        Response.End();
    }
    finally
    {
        // Close the PDF document
        if (pdfDocument != null)
            pdfDocument.Close();
    }
}