The sample demonstrates how to decrypt an encrypted PDF document and extract the embedded picture.

using System;
using System.Drawing;
using Spire.Pdf;

namespace Decryption
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a pdf document.
            String encryptedPdf = @"Encrypted.pdf";
            PdfDocument doc = new PdfDocument(encryptedPdf, "test");

            //extract image
            Image image = doc.Pages[0].ImagesInfo[0].Image;

            doc.Close();

            //Save image file.
            image.Save("Wikipedia_Science.png", System.Drawing.Imaging.ImageFormat.Png);

            //Launching the image file.
            System.Diagnostics.Process.Start("Wikipedia_Science.png");
        }
    }
}

Imports System.Drawing
Imports Spire.Pdf

Namespace Decryption
    Friend Class Program
        Shared Sub Main(ByVal args() As String)
            'Create a pdf document.
            Dim encryptedPdf As String = "Encrypted.pdf"
            Dim doc As New PdfDocument(encryptedPdf, "test")

            'extract image
            Dim image As Image = doc.Pages(0).ImagesInfo(0).Image

            doc.Close()

            'Save image file.
            image.Save("Wikipedia_Science.png", System.Drawing.Imaging.ImageFormat.Png)

            'Launching the image file.
            Process.Start("Wikipedia_Science.png")
        End Sub
    End Class
End Namespace

The sample demonstrates how to encrypt an PDF document and set owner/user password.

Download Encryption.pdf

using System;
using System.Drawing;
using Spire.Pdf;
using Spire.Pdf.Graphics;
using Spire.Pdf.Security;

namespace Encryption
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a pdf document.
            PdfDocument doc = new PdfDocument();

            // Create one page
            PdfPageBase page = doc.Pages.Add();

            //Draw the page
            DrawPage(page);

            //encrypt
            doc.Security.KeySize = PdfEncryptionKeySize.Key128Bit;
            doc.Security.OwnerPassword = "e-iceblue";
            doc.Security.UserPassword = "test";
            doc.Security.Permissions = PdfPermissionsFlags.Print | PdfPermissionsFlags.FillFields;

            //Save pdf file.
            doc.SaveToFile("Encryption.pdf");
            doc.Close();

            //Launching the Pdf file.
            System.Diagnostics.Process.Start("Encryption.pdf");
        }

        private static void DrawPage(PdfPageBase page)
        {
            float pageWidth = page.Canvas.ClientSize.Width;
            float y = 0;

            //page header
            PdfPen pen1 = new PdfPen(Color.LightGray, 1f);
            PdfBrush brush1 = new PdfSolidBrush(Color.LightGray);
            PdfTrueTypeFont font1 = new PdfTrueTypeFont(new Font("Arial", 8f, FontStyle.Italic));
            PdfStringFormat format1 = new PdfStringFormat(PdfTextAlignment.Right);
            String text = "Demo of Spire.Pdf";
            page.Canvas.DrawString(text, font1, brush1, pageWidth, y, format1);
            SizeF size = font1.MeasureString(text, format1);
            y = y + size.Height + 1;
            page.Canvas.DrawLine(pen1, 0, y, pageWidth, y);

            //title
            y = y + 5;
            PdfBrush brush2 = new PdfSolidBrush(Color.Black);
            PdfTrueTypeFont font2 = new PdfTrueTypeFont(new Font("Arial", 16f, FontStyle.Bold));
            PdfStringFormat format2 = new PdfStringFormat(PdfTextAlignment.Center);
            format2.CharacterSpacing = 1f;
            text = "Summary of Science";
            page.Canvas.DrawString(text, font2, brush2, pageWidth / 2, y, format2);
            size = font2.MeasureString(text, format2);
            y = y + size.Height + 6;

            //icon
            PdfImage image = PdfImage.FromFile(@"Wikipedia_Science.png");
            page.Canvas.DrawImage(image, new PointF(pageWidth - image.PhysicalDimension.Width, y));
            float imageLeftSpace = pageWidth - image.PhysicalDimension.Width - 2;
            float imageBottom = image.PhysicalDimension.Height + y;

            //refenrence content
            PdfTrueTypeFont font3 = new PdfTrueTypeFont(new Font("Arial", 9f));
            PdfStringFormat format3 = new PdfStringFormat();
            format3.ParagraphIndent = font3.Size * 2;
            format3.MeasureTrailingSpaces = true;
            format3.LineSpacing = font3.Size * 1.5f;
            String text1 = "(All text and picture from ";
            String text2 = "Wikipedia";
            String text3 = ", the free encyclopedia)";
            page.Canvas.DrawString(text1, font3, brush2, 0, y, format3);

            size = font3.MeasureString(text1, format3);
            float x1 = size.Width;
            format3.ParagraphIndent = 0;
            PdfTrueTypeFont font4 = new PdfTrueTypeFont(new Font("Arial", 9f, FontStyle.Underline));
            PdfBrush brush3 = PdfBrushes.Blue;
            page.Canvas.DrawString(text2, font4, brush3, x1, y, format3);
            size = font4.MeasureString(text2, format3);
            x1 = x1 + size.Width;

            page.Canvas.DrawString(text3, font3, brush2, x1, y, format3);
            y = y + size.Height;

            //content
            PdfStringFormat format4 = new PdfStringFormat();
            text = System.IO.File.ReadAllText(@"Summary_of_Science.txt");
            PdfTrueTypeFont font5 = new PdfTrueTypeFont(new Font("Arial", 10f));
            format4.LineSpacing = font5.Size * 1.5f;
            PdfStringLayouter textLayouter = new PdfStringLayouter();
            float imageLeftBlockHeight = imageBottom - y;
            PdfStringLayoutResult result
                = textLayouter.Layout(text, font5, format4, new SizeF(imageLeftSpace, imageLeftBlockHeight));
            if (result.ActualSize.Height < imageBottom - y)
            {
                imageLeftBlockHeight = imageLeftBlockHeight + result.LineHeight;
                result = textLayouter.Layout(text, font5, format4, new SizeF(imageLeftSpace, imageLeftBlockHeight));
            }
            foreach (LineInfo line in result.Lines)
            {
                page.Canvas.DrawString(line.Text, font5, brush2, 0, y, format4);
                y = y + result.LineHeight;
            }
            PdfTextWidget textWidget = new PdfTextWidget(result.Remainder, font5, brush2);
            PdfTextLayout textLayout = new PdfTextLayout();
            textLayout.Break = PdfLayoutBreakType.FitPage;
            textLayout.Layout = PdfLayoutType.Paginate;
            RectangleF bounds = new RectangleF(new PointF(0, y), page.Canvas.ClientSize);
            textWidget.StringFormat = format4;
            textWidget.Draw(page, bounds, textLayout);
        }
    }
}

Imports System.Drawing
Imports Spire.Pdf
Imports Spire.Pdf.Graphics
Imports Spire.Pdf.Security

Namespace Encryption
    Friend Class Program
        Shared Sub Main(ByVal args() As String)
            'Create a pdf document.
            Dim doc As New PdfDocument()

            ' Create one page
            Dim page As PdfPageBase = doc.Pages.Add()

            'Draw the page
            DrawPage(page)

            'encrypt
            doc.Security.KeySize = PdfEncryptionKeySize.Key128Bit
            doc.Security.OwnerPassword = "e-iceblue"
            doc.Security.UserPassword = "test"
            doc.Security.Permissions = PdfPermissionsFlags.Print Or PdfPermissionsFlags.FillFields

            'Save pdf file.
            doc.SaveToFile("Encryption.pdf")
            doc.Close()

            'Launching the Pdf file.
            Process.Start("Encryption.pdf")
        End Sub

        Private Shared Sub DrawPage(ByVal page As PdfPageBase)
            Dim pageWidth As Single = page.Canvas.ClientSize.Width
            Dim y As Single = 0

            'page header
            Dim pen1 As New PdfPen(Color.LightGray, 1.0F)
            Dim brush1 As PdfBrush = New PdfSolidBrush(Color.LightGray)
            Dim font1 As New PdfTrueTypeFont(New Font("Arial", 8.0F, FontStyle.Italic))
            Dim format1 As New PdfStringFormat(PdfTextAlignment.Right)
            Dim text As String = "Demo of Spire.Pdf"
            page.Canvas.DrawString(text, font1, brush1, pageWidth, y, format1)
            Dim size As SizeF = font1.MeasureString(text, format1)
            y = y + size.Height + 1
            page.Canvas.DrawLine(pen1, 0, y, pageWidth, y)

            'title
            y = y + 5
            Dim brush2 As PdfBrush = New PdfSolidBrush(Color.Black)
            Dim font2 As New PdfTrueTypeFont(New Font("Arial", 16.0F, FontStyle.Bold))
            Dim format2 As New PdfStringFormat(PdfTextAlignment.Center)
            format2.CharacterSpacing = 1.0F
            text = "Summary of Science"
            page.Canvas.DrawString(text, font2, brush2, pageWidth / 2, y, format2)
            size = font2.MeasureString(text, format2)
            y = y + size.Height + 6

            'icon
            Dim image As PdfImage = PdfImage.FromFile("Wikipedia_Science.png")
            page.Canvas.DrawImage(image, New PointF(pageWidth - image.PhysicalDimension.Width, y))
            Dim imageLeftSpace As Single = pageWidth - image.PhysicalDimension.Width - 2
            Dim imageBottom As Single = image.PhysicalDimension.Height + y

            'refenrence content
            Dim font3 As New PdfTrueTypeFont(New Font("Arial", 9.0F))
            Dim format3 As New PdfStringFormat()
            format3.ParagraphIndent = font3.Size * 2
            format3.MeasureTrailingSpaces = True
            format3.LineSpacing = font3.Size * 1.5F
            Dim text1 As String = "(All text and picture from "
            Dim text2 As String = "Wikipedia"
            Dim text3 As String = ", the free encyclopedia)"
            page.Canvas.DrawString(text1, font3, brush2, 0, y, format3)

            size = font3.MeasureString(text1, format3)
            Dim x1 As Single = size.Width
            format3.ParagraphIndent = 0
            Dim font4 As New PdfTrueTypeFont(New Font("Arial", 9.0F, FontStyle.Underline))
            Dim brush3 As PdfBrush = PdfBrushes.Blue
            page.Canvas.DrawString(text2, font4, brush3, x1, y, format3)
            size = font4.MeasureString(text2, format3)
            x1 = x1 + size.Width

            page.Canvas.DrawString(text3, font3, brush2, x1, y, format3)
            y = y + size.Height

            'content
            Dim format4 As New PdfStringFormat()
            text = System.IO.File.ReadAllText("Summary_of_Science.txt")
            Dim font5 As New PdfTrueTypeFont(New Font("Arial", 10.0F))
            format4.LineSpacing = font5.Size * 1.5F
            Dim textLayouter As New PdfStringLayouter()
            Dim imageLeftBlockHeight As Single = imageBottom - y
            Dim result As PdfStringLayoutResult _
                = textLayouter.Layout(text, font5, format4, New SizeF(imageLeftSpace, imageLeftBlockHeight))
            If result.ActualSize.Height < imageBottom - y Then
                imageLeftBlockHeight = imageLeftBlockHeight + result.LineHeight
                result = textLayouter.Layout(text, font5, format4, New SizeF(imageLeftSpace, imageLeftBlockHeight))
            End If
            For Each line As LineInfo In result.Lines
                page.Canvas.DrawString(line.Text, font5, brush2, 0, y, format4)
                y = y + result.LineHeight
            Next line
            Dim textWidget As New PdfTextWidget(result.Remainder, font5, brush2)
            Dim textLayout As New PdfTextLayout()
            textLayout.Break = PdfLayoutBreakType.FitPage
            textLayout.Layout = PdfLayoutType.Paginate
            Dim bounds As New RectangleF(New PointF(0, y), page.Canvas.ClientSize)
            textWidget.StringFormat = format4
            textWidget.Draw(page, bounds, textLayout)
        End Sub
    End Class
End Namespace

The sample demonstrates how to work with form, text box, check box, radio button, list box, combo box, button and form action in PDF document.

Download FormField.pdf

using System;
using System.Drawing;
using System.IO;
using System.Xml.XPath;
using Spire.Pdf;
using Spire.Pdf.Actions;
using Spire.Pdf.AutomaticFields;
using Spire.Pdf.Fields;
using Spire.Pdf.Graphics;

namespace FormField
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a pdf document.
            PdfDocument doc = new PdfDocument();

            //margin
            PdfUnitConvertor unitCvtr = new PdfUnitConvertor();
            PdfMargins margin = new PdfMargins();
            margin.Top = unitCvtr.ConvertUnits(2.54f, PdfGraphicsUnit.Centimeter, PdfGraphicsUnit.Point);
            margin.Bottom = margin.Top;
            margin.Left = unitCvtr.ConvertUnits(3.17f, PdfGraphicsUnit.Centimeter, PdfGraphicsUnit.Point);
            margin.Right = margin.Left;

            SetDocumentTemplate(doc, PdfPageSize.A4, margin);

            // Create one page
            PdfPageBase page = doc.Pages.Add(PdfPageSize.A4, new PdfMargins(0));

            float y = 0;

            //title
            y = DrawPageTitle(page, y);

            //load form config data
            using (Stream stream = File.OpenRead(@"Form.xml"))
            {
                XPathDocument xpathDoc = new XPathDocument(stream);
                XPathNodeIterator sectionNodes = xpathDoc.CreateNavigator().Select("/form/section");
                int fieldIndex = 0;
                foreach (XPathNavigator sectionNode in sectionNodes)
                {
                    //draw section label
                    String sectionLabel = sectionNode.GetAttribute("name", "");
                    y = DrawFormSection(sectionLabel, page, y);

                    XPathNodeIterator fieldNodes = sectionNode.Select("field");
                    foreach (XPathNavigator fieldNode in fieldNodes)
                    {
                        y = DrawFormField(fieldNode, doc.Form, page, y, fieldIndex++);
                    }
                }
            }

            //draw button
            y = y + 10;
            float buttonWidth = 80;
            float buttonX = (page.Canvas.ClientSize.Width - buttonWidth) / 2;
            RectangleF buttonBounds = new RectangleF(buttonX, y, buttonWidth, 16f);
            PdfButtonField button = new PdfButtonField(page, "submit");
            button.Text = "Submit";
            button.Bounds = buttonBounds;
            PdfSubmitAction submitAction = new PdfSubmitAction("http://www.e-iceblue.com");
            button.Actions.MouseUp = submitAction;
            doc.Form.Fields.Add(button);

            //Save pdf file.
            doc.SaveToFile("FormField.pdf");
            doc.Close();

            //Launching the Pdf file.
            System.Diagnostics.Process.Start("FormField.pdf");
        }
        private static void SetDocumentTemplate(PdfDocument doc, SizeF pageSize, PdfMargins margin)
        {
            PdfPageTemplateElement leftSpace
                = new PdfPageTemplateElement(margin.Left, pageSize.Height);
            doc.Template.Left = leftSpace;

            PdfPageTemplateElement topSpace
                = new PdfPageTemplateElement(pageSize.Width, margin.Top);
            topSpace.Foreground = true;
            doc.Template.Top = topSpace;

            //draw header label
            PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Arial", 9f, FontStyle.Italic));
            PdfStringFormat format = new PdfStringFormat(PdfTextAlignment.Right);
            String label = "Demo of Spire.Pdf";
            SizeF size = font.MeasureString(label, format);
            float y = topSpace.Height - font.Height - 1;
            PdfPen pen = new PdfPen(Color.Black, 0.75f);
            topSpace.Graphics.SetTransparency(0.5f);
            topSpace.Graphics.DrawLine(pen, margin.Left, y, pageSize.Width - margin.Right, y);
            y = y - 1 - size.Height;
            topSpace.Graphics.DrawString(label, font, PdfBrushes.Black, pageSize.Width - margin.Right, y, format);

            PdfPageTemplateElement rightSpace
                = new PdfPageTemplateElement(margin.Right, pageSize.Height);
            doc.Template.Right = rightSpace;

            PdfPageTemplateElement bottomSpace
                = new PdfPageTemplateElement(pageSize.Width, margin.Bottom);
            bottomSpace.Foreground = true;
            doc.Template.Bottom = bottomSpace;

            //draw footer label
            y = font.Height + 1;
            bottomSpace.Graphics.SetTransparency(0.5f);
            bottomSpace.Graphics.DrawLine(pen, margin.Left, y, pageSize.Width - margin.Right, y);
            y = y + 1;
            PdfPageNumberField pageNumber = new PdfPageNumberField();
            PdfPageCountField pageCount = new PdfPageCountField();
            PdfCompositeField pageNumberLabel = new PdfCompositeField();
            pageNumberLabel.AutomaticFields
                = new PdfAutomaticField[] { pageNumber, pageCount };
            pageNumberLabel.Brush = PdfBrushes.Black;
            pageNumberLabel.Font = font;
            pageNumberLabel.StringFormat = format;
            pageNumberLabel.Text = "page {0} of {1}";
            pageNumberLabel.Draw(bottomSpace.Graphics, pageSize.Width - margin.Right, y);

            PdfImage headerImage
                = PdfImage.FromFile(@"Header.png");
            PointF pageLeftTop = new PointF(-margin.Left, -margin.Top);
            PdfPageTemplateElement header = new PdfPageTemplateElement(pageLeftTop, headerImage.PhysicalDimension);
            header.Foreground = false;
            header.Graphics.SetTransparency(0.5f);
            header.Graphics.DrawImage(headerImage, 0, 0);
            doc.Template.Stamps.Add(header);

            PdfImage footerImage
                = PdfImage.FromFile(@"Footer.png");
            y = pageSize.Height - footerImage.PhysicalDimension.Height;
            PointF footerLocation = new PointF(-margin.Left, y);
            PdfPageTemplateElement footer = new PdfPageTemplateElement(footerLocation, footerImage.PhysicalDimension);
            footer.Foreground = false;
            footer.Graphics.SetTransparency(0.5f);
            footer.Graphics.DrawImage(footerImage, 0, 0);
            doc.Template.Stamps.Add(footer);
        }

        private static float DrawPageTitle(PdfPageBase page, float y)
        {
            PdfBrush brush1 = PdfBrushes.MidnightBlue;
            PdfBrush brush2 = PdfBrushes.Red;
            PdfTrueTypeFont font1 = new PdfTrueTypeFont(new Font("Arial", 12f, FontStyle.Bold));
            String title = "Your Account Information(* = Required)";
            SizeF size = font1.MeasureString(title);
            float x = (page.Canvas.ClientSize.Width - size.Width) / 2;
            page.Canvas.DrawString("Your Account Information(", font1, brush1, x, y);
            size = font1.MeasureString("Your Account Information(");
            x = x + size.Width;
            page.Canvas.DrawString("* = Required", font1, brush2, x, y);
            size = font1.MeasureString("* = Required");
            x = x + size.Width;
            page.Canvas.DrawString(")", font1, brush1, x, y);
            y = y + size.Height;

            y = y + 3;
            PdfTrueTypeFont font2 = new PdfTrueTypeFont(new Font("Arial", 8f, FontStyle.Italic));
            String p = "Your information is not public, shared in anyway, or displayed on this site.";
            page.Canvas.DrawString(p, font2, brush1, 0, y);

            return y + font2.Height;
        }

        private static float DrawFormSection(String label, PdfPageBase page, float y)
        {
            PdfBrush brush1 = PdfBrushes.LightYellow;
            PdfBrush brush2 = PdfBrushes.DarkSlateGray;
            PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Arial", 9f, FontStyle.Bold));
            PdfStringFormat format = new PdfStringFormat();
            float height = font.MeasureString(label).Height;
            page.Canvas.DrawRectangle(brush2, 0, y, page.Canvas.ClientSize.Width, height + 2);
            page.Canvas.DrawString(label, font, brush1, 2, y + 1);
            y = y + height + 2;
            PdfPen pen = new PdfPen(PdfBrushes.LightSkyBlue, 0.75f);
            page.Canvas.DrawLine(pen, 0, y, page.Canvas.ClientSize.Width, y);
            return y + 0.75f;
        }

        private static float DrawFormField(XPathNavigator fieldNode, PdfForm form, PdfPageBase page, float y, int fieldIndex)
        {
            float width = page.Canvas.ClientSize.Width;
            float padding = 2;

            //measure field label
            String label = fieldNode.GetAttribute("label", "");
            PdfTrueTypeFont font1 = new PdfTrueTypeFont(new Font("Arial", 9f));
            PdfStringFormat format = new PdfStringFormat(PdfTextAlignment.Right, PdfVerticalAlignment.Middle);
            float labelMaxWidth = width * 0.4f - 2 * padding;
            SizeF labelSize = font1.MeasureString(label, labelMaxWidth, format);

            //measure field height
            float fieldHeight = MeasureFieldHeight(fieldNode);

            float height = labelSize.Height > fieldHeight ? labelSize.Height : fieldHeight;
            height = height + 2;

            //draw background
            PdfBrush brush = PdfBrushes.SteelBlue;
            if (fieldIndex % 2 == 1)
            {
                brush = PdfBrushes.LightGreen;
            }
            page.Canvas.DrawRectangle(brush, 0, y, width, height);

            //draw field label
            PdfBrush brush1 = PdfBrushes.LightYellow;
            RectangleF labelBounds = new RectangleF(padding, y, labelMaxWidth, height);
            page.Canvas.DrawString(label, font1, brush1, labelBounds, format);

            //daw field
            float fieldMaxWidth = width * 0.57f - 2 * padding;
            float fieldX = labelBounds.Right + 2 * padding;
            float fieldY = y + (height - fieldHeight) / 2;
            String fieldType = fieldNode.GetAttribute("type", "");
            String fieldId = fieldNode.GetAttribute("id", "");
            bool required = "true" == fieldNode.GetAttribute("required", "");
            switch (fieldType)
            {
                case "text":
                case "password":
                    PdfTextBoxField textField = new PdfTextBoxField(page, fieldId);
                    textField.Bounds = new RectangleF(fieldX, fieldY, fieldMaxWidth, fieldHeight);
                    textField.BorderWidth = 0.75f;
                    textField.BorderStyle = PdfBorderStyle.Solid;
                    textField.Required = required;
                    if ("password" == fieldType)
                    {
                        textField.Password = true;
                    }
                    if ("true" == fieldNode.GetAttribute("multiple", ""))
                    {
                        textField.Multiline = true;
                        textField.Scrollable = true;
                    }
                    form.Fields.Add(textField);
                    break;
                case "checkbox":
                    PdfCheckBoxField checkboxField = new PdfCheckBoxField(page, fieldId);
                    float checkboxWidth = fieldHeight - 2 * padding;
                    float checkboxHeight = checkboxWidth;
                    checkboxField.Bounds = new RectangleF(fieldX, fieldY + padding, checkboxWidth, checkboxHeight);
                    checkboxField.BorderWidth = 0.75f;
                    checkboxField.Style = PdfCheckBoxStyle.Cross;
                    checkboxField.Required = required;
                    form.Fields.Add(checkboxField);
                    break;

                case "list":
                    XPathNodeIterator itemNodes = fieldNode.Select("item");
                    if ("true" == fieldNode.GetAttribute("multiple", ""))
                    {
                        PdfListBoxField listBoxField = new PdfListBoxField(page, fieldId);
                        listBoxField.Bounds = new RectangleF(fieldX, fieldY, fieldMaxWidth, fieldHeight);
                        listBoxField.BorderWidth = 0.75f;
                        listBoxField.MultiSelect = true;
                        listBoxField.Font = new PdfFont(PdfFontFamily.Helvetica, 9f);
                        listBoxField.Required = required;
                        //add items into list box.
                        foreach (XPathNavigator itemNode in itemNodes)
                        {
                            String text = itemNode.SelectSingleNode("text()").Value;
                            listBoxField.Items.Add(new PdfListFieldItem(text, text));
                        }
                        listBoxField.SelectedIndex = 0;
                        form.Fields.Add(listBoxField);

                        break;
                    }
                    if (itemNodes != null && itemNodes.Count <= 3)
                    {
                        PdfRadioButtonListField radioButtonListFile
                            = new PdfRadioButtonListField(page, fieldId);
                        radioButtonListFile.Required = required;
                        //add items into radio button list.
                        float fieldItemHeight = fieldHeight / itemNodes.Count;
                        float radioButtonWidth = fieldItemHeight - 2 * padding;
                        float radioButtonHeight = radioButtonWidth;
                        foreach (XPathNavigator itemNode in itemNodes)
                        {
                            String text = itemNode.SelectSingleNode("text()").Value;
                            PdfRadioButtonListItem fieldItem = new PdfRadioButtonListItem(text);
                            fieldItem.BorderWidth = 0.75f;
                            fieldItem.Bounds = new RectangleF(fieldX, fieldY + padding, radioButtonWidth, radioButtonHeight);
                            radioButtonListFile.Items.Add(fieldItem);

                            float fieldItemLabelX = fieldX + radioButtonWidth + padding;
                            SizeF fieldItemLabelSize = font1.MeasureString(text);
                            float fieldItemLabelY = fieldY + (fieldItemHeight - fieldItemLabelSize.Height) / 2;
                            page.Canvas.DrawString(text, font1, brush1, fieldItemLabelX, fieldItemLabelY);

                            fieldY = fieldY + fieldItemHeight;
                        }
                        form.Fields.Add(radioButtonListFile);

                        break;
                    }

                    //combo box
                    PdfComboBoxField comboBoxField = new PdfComboBoxField(page, fieldId);
                    comboBoxField.Bounds = new RectangleF(fieldX, fieldY, fieldMaxWidth, fieldHeight);
                    comboBoxField.BorderWidth = 0.75f;
                    comboBoxField.Font = new PdfFont(PdfFontFamily.Helvetica, 9f);
                    comboBoxField.Required = required;
                    //add items into combo box.
                    foreach (XPathNavigator itemNode in itemNodes)
                    {
                        String text = itemNode.SelectSingleNode("text()").Value;
                        comboBoxField.Items.Add(new PdfListFieldItem(text, text));
                    }
                    form.Fields.Add(comboBoxField);
                    break;

            }

            if (required)
            {
                //draw *
                float flagX = width * 0.97f + padding;
                PdfTrueTypeFont font3 = new PdfTrueTypeFont(new Font("Arial", 10f, FontStyle.Bold));
                SizeF size = font3.MeasureString("*");
                float flagY = y + (height - size.Height) / 2;
                page.Canvas.DrawString("*", font3, PdfBrushes.Red, flagX, flagY);
            }

            return y + height;
        }

        private static float MeasureFieldHeight(XPathNavigator fieldNode)
        {
            String fieldType = fieldNode.GetAttribute("type", "");
            float defaultHeight = 16f;
            switch (fieldType)
            {
                case "text":
                case "password":
                    if ("true" == fieldNode.GetAttribute("multiple", ""))
                    {
                        return defaultHeight * 3;
                    }
                    return defaultHeight;

                case "checkbox":
                    return defaultHeight;

                case "list":
                    if ("true" == fieldNode.GetAttribute("multiple", ""))
                    {
                        return defaultHeight * 3;
                    }
                    XPathNodeIterator itemNodes = fieldNode.Select("item");
                    if (itemNodes != null && itemNodes.Count <= 3)
                    {
                        return defaultHeight * 3;
                    }
                    return defaultHeight;

            }
            String message = String.Format("Invalid field type: {0}", fieldType);
            throw new ArgumentException(message);
        }
    }
}

Imports System.Drawing
Imports System.IO
Imports System.Xml.XPath
Imports Spire.Pdf
Imports Spire.Pdf.Actions
Imports Spire.Pdf.AutomaticFields
Imports Spire.Pdf.Fields
Imports Spire.Pdf.Graphics

Namespace FormField
    Friend Class Program
        Shared Sub Main(ByVal args() As String)
            'Create a pdf document.
            Dim doc As New PdfDocument()

            'margin
            Dim unitCvtr As New PdfUnitConvertor()
            Dim margin As New PdfMargins()
            margin.Top = unitCvtr.ConvertUnits(2.54F, PdfGraphicsUnit.Centimeter, PdfGraphicsUnit.Point)
            margin.Bottom = margin.Top
            margin.Left = unitCvtr.ConvertUnits(3.17F, PdfGraphicsUnit.Centimeter, PdfGraphicsUnit.Point)
            margin.Right = margin.Left

            SetDocumentTemplate(doc, PdfPageSize.A4, margin)

            ' Create one page
            Dim page As PdfPageBase = doc.Pages.Add(PdfPageSize.A4, New PdfMargins(0))

            Dim y As Single = 0

            'title
            y = DrawPageTitle(page, y)

            'load form config data
            Using stream As Stream = File.OpenRead("Form.xml")
                Dim xpathDoc As New XPathDocument(stream)
                Dim sectionNodes As XPathNodeIterator = xpathDoc.CreateNavigator().Select("/form/section")
                Dim fieldIndex As Integer = 0
                For Each sectionNode As XPathNavigator In sectionNodes
                    'draw section label
                    Dim sectionLabel As String = sectionNode.GetAttribute("name", "")
                    y = DrawFormSection(sectionLabel, page, y)

                    Dim fieldNodes As XPathNodeIterator = sectionNode.Select("field")
                    For Each fieldNode As XPathNavigator In fieldNodes
                        y = DrawFormField(fieldNode, doc.Form, page, y, fieldIndex)
                        fieldIndex += 1
                    Next fieldNode
                Next sectionNode
            End Using

            'draw button
            y = y + 10
            Dim buttonWidth As Single = 80
            Dim buttonX As Single = (page.Canvas.ClientSize.Width - buttonWidth) / 2
            Dim buttonBounds As New RectangleF(buttonX, y, buttonWidth, 16.0F)
            Dim button As New PdfButtonField(page, "submit")
            button.Text = "Submit"
            button.Bounds = buttonBounds
            Dim submitAction As New PdfSubmitAction("http://www.e-iceblue.com")
            button.Actions.MouseUp = submitAction
            doc.Form.Fields.Add(button)

            'Save pdf file.
            doc.SaveToFile("FormField.pdf")
            doc.Close()

            'Launching the Pdf file.
            Process.Start("FormField.pdf")
        End Sub
        Private Shared Sub SetDocumentTemplate(ByVal doc As PdfDocument, ByVal pageSize As SizeF, _
                                               ByVal margin As PdfMargins)
            Dim leftSpace As New PdfPageTemplateElement(margin.Left, pageSize.Height)
            doc.Template.Left = leftSpace

            Dim topSpace As New PdfPageTemplateElement(pageSize.Width, margin.Top)
            topSpace.Foreground = True
            doc.Template.Top = topSpace

            'draw header label
            Dim font As New PdfTrueTypeFont(New Font("Arial", 9.0F, FontStyle.Italic))
            Dim format As New PdfStringFormat(PdfTextAlignment.Right)
            Dim label As String = "Demo of Spire.Pdf"
            Dim size As SizeF = font.MeasureString(label, format)
            Dim y As Single = topSpace.Height - font.Height - 1
            Dim pen As New PdfPen(Color.Black, 0.75F)
            topSpace.Graphics.SetTransparency(0.5F)
            topSpace.Graphics.DrawLine(pen, margin.Left, y, pageSize.Width - margin.Right, y)
            y = y - 1 - size.Height
            topSpace.Graphics.DrawString(label, font, PdfBrushes.Black, pageSize.Width - margin.Right, y, format)

            Dim rightSpace As New PdfPageTemplateElement(margin.Right, pageSize.Height)
            doc.Template.Right = rightSpace

            Dim bottomSpace As New PdfPageTemplateElement(pageSize.Width, margin.Bottom)
            bottomSpace.Foreground = True
            doc.Template.Bottom = bottomSpace

            'draw footer label
            y = font.Height + 1
            bottomSpace.Graphics.SetTransparency(0.5F)
            bottomSpace.Graphics.DrawLine(pen, margin.Left, y, pageSize.Width - margin.Right, y)
            y = y + 1
            Dim pageNumber As New PdfPageNumberField()
            Dim pageCount As New PdfPageCountField()
            Dim pageNumberLabel As New PdfCompositeField()
            pageNumberLabel.AutomaticFields = New PdfAutomaticField() {pageNumber, pageCount}
            pageNumberLabel.Brush = PdfBrushes.Black
            pageNumberLabel.Font = font
            pageNumberLabel.StringFormat = format
            pageNumberLabel.Text = "page {0} of {1}"
            pageNumberLabel.Draw(bottomSpace.Graphics, pageSize.Width - margin.Right, y)

            Dim headerImage As PdfImage = PdfImage.FromFile("Header.png")
            Dim pageLeftTop As New PointF(-margin.Left, -margin.Top)
            Dim header As New PdfPageTemplateElement(pageLeftTop, headerImage.PhysicalDimension)
            header.Foreground = False
            header.Graphics.SetTransparency(0.5F)
            header.Graphics.DrawImage(headerImage, 0, 0)
            doc.Template.Stamps.Add(header)

            Dim footerImage As PdfImage = PdfImage.FromFile("Footer.png")
            y = pageSize.Height - footerImage.PhysicalDimension.Height
            Dim footerLocation As New PointF(-margin.Left, y)
            Dim footer As New PdfPageTemplateElement(footerLocation, footerImage.PhysicalDimension)
            footer.Foreground = False
            footer.Graphics.SetTransparency(0.5F)
            footer.Graphics.DrawImage(footerImage, 0, 0)
            doc.Template.Stamps.Add(footer)
        End Sub

        Private Shared Function DrawPageTitle(ByVal page As PdfPageBase, ByVal y As Single) As Single
            Dim brush1 As PdfBrush = PdfBrushes.MidnightBlue
            Dim brush2 As PdfBrush = PdfBrushes.Red
            Dim font1 As New PdfTrueTypeFont(New Font("Arial", 12.0F, FontStyle.Bold))
            Dim title As String = "Your Account Information(* = Required)"
            Dim size As SizeF = font1.MeasureString(title)
            Dim x As Single = (page.Canvas.ClientSize.Width - size.Width) / 2
            page.Canvas.DrawString("Your Account Information(", font1, brush1, x, y)
            size = font1.MeasureString("Your Account Information(")
            x = x + size.Width
            page.Canvas.DrawString("* = Required", font1, brush2, x, y)
            size = font1.MeasureString("* = Required")
            x = x + size.Width
            page.Canvas.DrawString(")", font1, brush1, x, y)
            y = y + size.Height

            y = y + 3
            Dim font2 As New PdfTrueTypeFont(New Font("Arial", 8.0F, FontStyle.Italic))
            Dim p As String = "Your information is not public, shared in anyway, or displayed on this site."
            page.Canvas.DrawString(p, font2, brush1, 0, y)

            Return y + font2.Height
        End Function

        Private Shared Function DrawFormSection(ByVal label As String, ByVal page As PdfPageBase, _
                                                ByVal y As Single) As Single
            Dim brush1 As PdfBrush = PdfBrushes.LightYellow
            Dim brush2 As PdfBrush = PdfBrushes.DarkSlateGray
            Dim font As New PdfTrueTypeFont(New Font("Arial", 9.0F, FontStyle.Bold))
            Dim format As New PdfStringFormat()
            Dim height As Single = font.MeasureString(label).Height
            page.Canvas.DrawRectangle(brush2, 0, y, page.Canvas.ClientSize.Width, height + 2)
            page.Canvas.DrawString(label, font, brush1, 2, y + 1)
            y = y + height + 2
            Dim pen As New PdfPen(PdfBrushes.LightSkyBlue, 0.75F)
            page.Canvas.DrawLine(pen, 0, y, page.Canvas.ClientSize.Width, y)
            Return y + 0.75F
        End Function

        Private Shared Function DrawFormField(ByVal fieldNode As XPathNavigator, ByVal form As PdfForm, _
                    ByVal page As PdfPageBase, ByVal y As Single, ByVal fieldIndex As Integer) As Single
            Dim width As Single = page.Canvas.ClientSize.Width
            Dim padding As Single = 2

            'measure field label
            Dim label As String = fieldNode.GetAttribute("label", "")
            Dim font1 As New PdfTrueTypeFont(New Font("Arial", 9.0F))
            Dim format As New PdfStringFormat(PdfTextAlignment.Right, PdfVerticalAlignment.Middle)
            Dim labelMaxWidth As Single = width * 0.4F - 2 * padding
            Dim labelSize As SizeF = font1.MeasureString(label, labelMaxWidth, format)

            'measure field height
            Dim fieldHeight As Single = MeasureFieldHeight(fieldNode)

            Dim height As Single = If(labelSize.Height > fieldHeight, labelSize.Height, fieldHeight)
            height = height + 2

            'draw background
            Dim brush As PdfBrush = PdfBrushes.SteelBlue
            If fieldIndex Mod 2 = 1 Then
                brush = PdfBrushes.LightGreen
            End If
            page.Canvas.DrawRectangle(brush, 0, y, width, height)

            'draw field label
            Dim brush1 As PdfBrush = PdfBrushes.LightYellow
            Dim labelBounds As New RectangleF(padding, y, labelMaxWidth, height)
            page.Canvas.DrawString(label, font1, brush1, labelBounds, format)

            'daw field
            Dim fieldMaxWidth As Single = width * 0.57F - 2 * padding
            Dim fieldX As Single = labelBounds.Right + 2 * padding
            Dim fieldY As Single = y + (height - fieldHeight) / 2
            Dim fieldType As String = fieldNode.GetAttribute("type", "")
            Dim fieldId As String = fieldNode.GetAttribute("id", "")
            Dim required As Boolean = "true" = fieldNode.GetAttribute("required", "")
            Select Case fieldType
                Case "text", "password"
                    Dim textField As New PdfTextBoxField(page, fieldId)
                    textField.Bounds = New RectangleF(fieldX, fieldY, fieldMaxWidth, fieldHeight)
                    textField.BorderWidth = 0.75F
                    textField.BorderStyle = PdfBorderStyle.Solid
                    textField.Required = required
                    If "password" = fieldType Then
                        textField.Password = True
                    End If
                    If "true" = fieldNode.GetAttribute("multiple", "") Then
                        textField.Multiline = True
                        textField.Scrollable = True
                    End If
                    form.Fields.Add(textField)
                Case "checkbox"
                    Dim checkboxField As New PdfCheckBoxField(page, fieldId)
                    Dim checkboxWidth As Single = fieldHeight - 2 * padding
                    Dim checkboxHeight As Single = checkboxWidth
                    checkboxField.Bounds = New RectangleF(fieldX, fieldY + padding, checkboxWidth, checkboxHeight)
                    checkboxField.BorderWidth = 0.75F
                    checkboxField.Style = PdfCheckBoxStyle.Cross
                    checkboxField.Required = required
                    form.Fields.Add(checkboxField)

                Case "list"
                    Dim itemNodes As XPathNodeIterator = fieldNode.Select("item")
                    If "true" = fieldNode.GetAttribute("multiple", "") Then
                        Dim listBoxField As New PdfListBoxField(page, fieldId)
                        listBoxField.Bounds = New RectangleF(fieldX, fieldY, fieldMaxWidth, fieldHeight)
                        listBoxField.BorderWidth = 0.75F
                        listBoxField.MultiSelect = True
                        listBoxField.Font = New PdfFont(PdfFontFamily.Helvetica, 9.0F)
                        listBoxField.Required = required
                        'add items into list box.
                        For Each itemNode As XPathNavigator In itemNodes
                            Dim text As String = itemNode.SelectSingleNode("text()").Value
                            listBoxField.Items.Add(New PdfListFieldItem(text, text))
                        Next itemNode
                        listBoxField.SelectedIndex = 0
                        form.Fields.Add(listBoxField)

                        Exit Select
                    End If
                    If itemNodes IsNot Nothing AndAlso itemNodes.Count <= 3 Then
                        Dim radioButtonListFile As New PdfRadioButtonListField(page, fieldId)
                        radioButtonListFile.Required = required
                        'add items into radio button list.
                        Dim fieldItemHeight As Single = fieldHeight / itemNodes.Count
                        Dim radioButtonWidth As Single = fieldItemHeight - 2 * padding
                        Dim radioButtonHeight As Single = radioButtonWidth
                        For Each itemNode As XPathNavigator In itemNodes
                            Dim text As String = itemNode.SelectSingleNode("text()").Value
                            Dim fieldItem As New PdfRadioButtonListItem(text)
                            fieldItem.BorderWidth = 0.75F
                            fieldItem.Bounds = New RectangleF(fieldX, fieldY + padding, radioButtonWidth, radioButtonHeight)
                            radioButtonListFile.Items.Add(fieldItem)

                            Dim fieldItemLabelX As Single = fieldX + radioButtonWidth + padding
                            Dim fieldItemLabelSize As SizeF = font1.MeasureString(text)
                            Dim fieldItemLabelY As Single = fieldY + (fieldItemHeight - fieldItemLabelSize.Height) / 2
                            page.Canvas.DrawString(text, font1, brush1, fieldItemLabelX, fieldItemLabelY)

                            fieldY = fieldY + fieldItemHeight
                        Next itemNode
                        form.Fields.Add(radioButtonListFile)

                        Exit Select
                    End If

                    'combo box
                    Dim comboBoxField As New PdfComboBoxField(page, fieldId)
                    comboBoxField.Bounds = New RectangleF(fieldX, fieldY, fieldMaxWidth, fieldHeight)
                    comboBoxField.BorderWidth = 0.75F
                    comboBoxField.Font = New PdfFont(PdfFontFamily.Helvetica, 9.0F)
                    comboBoxField.Required = required
                    'add items into combo box.
                    For Each itemNode As XPathNavigator In itemNodes
                        Dim text As String = itemNode.SelectSingleNode("text()").Value
                        comboBoxField.Items.Add(New PdfListFieldItem(text, text))
                    Next itemNode
                    form.Fields.Add(comboBoxField)

            End Select

            If required Then
                'draw *
                Dim flagX As Single = width * 0.97F + padding
                Dim font3 As New PdfTrueTypeFont(New Font("Arial", 10.0F, FontStyle.Bold))
                Dim size As SizeF = font3.MeasureString("*")
                Dim flagY As Single = y + (height - size.Height) / 2
                page.Canvas.DrawString("*", font3, PdfBrushes.Red, flagX, flagY)
            End If

            Return y + height
        End Function

        Private Shared Function MeasureFieldHeight(ByVal fieldNode As XPathNavigator) As Single
            Dim fieldType As String = fieldNode.GetAttribute("type", "")
            Dim defaultHeight As Single = 16.0F
            Select Case fieldType
                Case "text", "password"
                    If "true" = fieldNode.GetAttribute("multiple", "") Then
                        Return defaultHeight * 3
                    End If
                    Return defaultHeight

                Case "checkbox"
                    Return defaultHeight

                Case "list"
                    If "true" = fieldNode.GetAttribute("multiple", "") Then
                        Return defaultHeight * 3
                    End If
                    Dim itemNodes As XPathNodeIterator = fieldNode.Select("item")
                    If itemNodes IsNot Nothing AndAlso itemNodes.Count <= 3 Then
                        Return defaultHeight * 3
                    End If
                    Return defaultHeight

            End Select
            Dim message As String = String.Format("Invalid field type: {0}", fieldType)
            Throw New ArgumentException(message)
        End Function
    End Class
End Namespace