PM> Install-Package Spire.PDF

using Spire.Pdf;
using Spire.Pdf.Actions;
using Spire.Pdf.Fields;
using Spire.Pdf.Graphics;
using System.Drawing;

namespace CreateFillableFormsInPdf
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a PdfDocument object
            PdfDocument doc = new PdfDocument();

            //Add a page
            PdfPageBase page = doc.Pages.Add();

            //Initialize x and y coordinates
            float baseX = 100;
            float baseY = 30;

            //Create two brush objects
            PdfSolidBrush brush1 = new PdfSolidBrush(new PdfRGBColor(Color.Blue));
            PdfSolidBrush brush2 = new PdfSolidBrush(new PdfRGBColor(Color.Black));

            //Create a font 
            PdfFont font = new PdfFont(PdfFontFamily.TimesRoman, 12f, PdfFontStyle.Regular);

            //Add a textbox 
            page.Canvas.DrawString("TextBox:", font, brush1, new PointF(10, baseY));
            RectangleF tbxBounds = new RectangleF(baseX, baseY, 150, 15);
            PdfTextBoxField textBox = new PdfTextBoxField(page, "textbox");
            textBox.Bounds = tbxBounds;
            textBox.Text = "Hello World";
            textBox.Font = font;
            doc.Form.Fields.Add(textBox);
            baseY += 25;

            //add two checkboxes 
            page.Canvas.DrawString("CheckBox:", font, brush1, new PointF(10, baseY));
            RectangleF checkboxBound1 = new RectangleF(baseX, baseY, 15, 15);
            PdfCheckBoxField checkBoxField1 = new PdfCheckBoxField(page, "checkbox1");
            checkBoxField1.Bounds = checkboxBound1;
            checkBoxField1.Checked = false;
            page.Canvas.DrawString("Option 1", font, brush2, new PointF(baseX + 20, baseY));

            RectangleF checkboxBound2 = new RectangleF(baseX + 70, baseY, 15, 15);
            PdfCheckBoxField checkBoxField2 = new PdfCheckBoxField(page, "checkbox2");
            checkBoxField2.Bounds = checkboxBound2;
            checkBoxField2.Checked = false;
            page.Canvas.DrawString("Option 2", font, brush2, new PointF(baseX + 90, baseY));
            doc.Form.Fields.Add(checkBoxField1);
            doc.Form.Fields.Add(checkBoxField2);
            baseY += 25;

            //Add a listbox
            page.Canvas.DrawString("ListBox:", font, brush1, new PointF(10, baseY));
            RectangleF listboxBound = new RectangleF(baseX, baseY, 150, 50);
            PdfListBoxField listBoxField = new PdfListBoxField(page, "listbox");
            listBoxField.Items.Add(new PdfListFieldItem("Item 1", "item1"));
            listBoxField.Items.Add(new PdfListFieldItem("Item 2", "item2"));
            listBoxField.Items.Add(new PdfListFieldItem("Item 3", "item3")); ;
            listBoxField.Bounds = listboxBound;
            listBoxField.Font = font;
            listBoxField.SelectedIndex = 0;
            doc.Form.Fields.Add(listBoxField);
            baseY += 60;

            //Add two radio buttons
            page.Canvas.DrawString("RadioButton:", font, brush1, new PointF(10, baseY));
            PdfRadioButtonListField radioButtonListField = new PdfRadioButtonListField(page, "radio");
            PdfRadioButtonListItem radioItem1 = new PdfRadioButtonListItem("option1");
            RectangleF radioBound1 = new RectangleF(baseX, baseY, 15, 15);
            radioItem1.Bounds = radioBound1;
            page.Canvas.DrawString("Option 1", font, brush2, new PointF(baseX + 20, baseY));

            PdfRadioButtonListItem radioItem2 = new PdfRadioButtonListItem("option2");
            RectangleF radioBound2 = new RectangleF(baseX + 70, baseY, 15, 15);
            radioItem2.Bounds = radioBound2;
            page.Canvas.DrawString("Option 2", font, brush2, new PointF(baseX + 90, baseY));
            radioButtonListField.Items.Add(radioItem1);
            radioButtonListField.Items.Add(radioItem2);
            radioButtonListField.SelectedIndex = 0;
            doc.Form.Fields.Add(radioButtonListField);
            baseY += 25;

            //Add a combobox
            page.Canvas.DrawString("ComboBox:", font, brush1, new PointF(10, baseY));
            RectangleF cmbBounds = new RectangleF(baseX, baseY, 150, 15);
            PdfComboBoxField comboBoxField = new PdfComboBoxField(page, "combobox");
            comboBoxField.Bounds = cmbBounds;
            comboBoxField.Items.Add(new PdfListFieldItem("Item 1", "item1"));
            comboBoxField.Items.Add(new PdfListFieldItem("Item 2", "itme2"));
            comboBoxField.Items.Add(new PdfListFieldItem("Item 3", "item3"));
            comboBoxField.Items.Add(new PdfListFieldItem("Item 4", "item4"));
            comboBoxField.SelectedIndex = 0;
            comboBoxField.Font = font;
            doc.Form.Fields.Add(comboBoxField);
            baseY += 25;

            //Add a signature field
            page.Canvas.DrawString("Signature Field:", font, brush1, new PointF(10, baseY));
            PdfSignatureField sgnField = new PdfSignatureField(page, "sgnField");
            RectangleF sgnBounds = new RectangleF(baseX, baseY, 150, 80);
            sgnField.Bounds = sgnBounds;
            doc.Form.Fields.Add(sgnField);
            baseY += 90;

            //Add a button
            page.Canvas.DrawString("Button:", font, brush1, new PointF(10, baseY));
            RectangleF btnBounds = new RectangleF(baseX, baseY, 50, 15);
            PdfButtonField buttonField = new PdfButtonField(page, "button");
            buttonField.Bounds = btnBounds;
            buttonField.Text = "Submit";
            buttonField.Font = font;
            PdfSubmitAction submitAction = new PdfSubmitAction("https://www.e-iceblue.com/getformvalues.php");
            submitAction.DataFormat = SubmitDataFormat.Html;
            buttonField.Actions.MouseDown = submitAction;
            doc.Form.Fields.Add(buttonField);

            //Save to file
            doc.SaveToFile("FillableForms.pdf", FileFormat.PDF);
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Actions
Imports Spire.Pdf.Fields
Imports Spire.Pdf.Graphics
Imports System.Drawing
 
Namespace CreateFillableFormsInPdf
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument() 
 
            'Add a page
            Dim page As PdfPageBase =  doc.Pages.Add() 
 
            'Initialize x and y coordinates
            Dim baseX As single =  100 
            Dim baseY As single =  30 
 
            'Create two brush objects
            Dim brush1 As PdfSolidBrush =  New PdfSolidBrush(New PdfRGBColor(Color.Blue)) 
            Dim brush2 As PdfSolidBrush =  New PdfSolidBrush(New PdfRGBColor(Color.Black)) 
 
            'Create a font 
            Dim font As PdfFont =  New PdfFont(PdfFontFamily.TimesRoman,12f,PdfFontStyle.Regular) 
 
            'Add a textbox 
            page.Canvas.DrawString("TextBox:",font,brush1,New PointF(10,baseY))
            Dim tbxBounds As RectangleF =  New RectangleF(baseX,baseY,150,15) 
            Dim textBox As PdfTextBoxField =  New PdfTextBoxField(page,"textbox") 
            textBox.Bounds = tbxBounds
            textBox.Text = "Hello World"
            textBox.Font = font
            doc.Form.Fields.Add(textBox)
            baseY += 25
 
            'add two checkboxes 
            page.Canvas.DrawString("CheckBox:",font,brush1,New PointF(10,baseY))
            Dim checkboxBound1 As RectangleF =  New RectangleF(baseX,baseY,15,15) 
            Dim checkBoxField1 As PdfCheckBoxField =  New PdfCheckBoxField(page,"checkbox1") 
            checkBoxField1.Bounds = checkboxBound1
            checkBoxField1.Checked = False
            page.Canvas.DrawString("Option 1", font, brush2, New PointF(baseX + 20, baseY))
 
            Dim checkboxBound2 As RectangleF =  New RectangleF(baseX + 70,baseY,15,15) 
            Dim checkBoxField2 As PdfCheckBoxField =  New PdfCheckBoxField(page,"checkbox2") 
            checkBoxField2.Bounds = checkboxBound2
            checkBoxField2.Checked = False
            page.Canvas.DrawString("Option 2", font, brush2, New PointF(baseX + 90, baseY))
            doc.Form.Fields.Add(checkBoxField1)
            doc.Form.Fields.Add(checkBoxField2)
            baseY += 25
 
            'Add a listbox
            page.Canvas.DrawString("ListBox:",font,brush1,New PointF(10,baseY))
            Dim listboxBound As RectangleF =  New RectangleF(baseX,baseY,150,50) 
            Dim listBoxField As PdfListBoxField =  New PdfListBoxField(page,"listbox") 
            listBoxField.Items.Add(New PdfListFieldItem("Item 1","item1"))
            listBoxField.Items.Add(New PdfListFieldItem("Item 2","item2"))
            listBoxField.Items.Add(New PdfListFieldItem("Item 3","item3"))
            listBoxField.Bounds = listboxBound
            listBoxField.Font = font
            listBoxField.SelectedIndex = 0
            doc.Form.Fields.Add(listBoxField)
            baseY += 60
 
            'Add two radio buttons
            page.Canvas.DrawString("RadioButton:",font,brush1,New PointF(10,baseY))
            Dim radioButtonListField As PdfRadioButtonListField =  New PdfRadioButtonListField(page,"radio") 
            Dim radioItem1 As PdfRadioButtonListItem =  New PdfRadioButtonListItem("option1") 
            Dim radioBound1 As RectangleF =  New RectangleF(baseX,baseY,15,15) 
            radioItem1.Bounds = radioBound1
            page.Canvas.DrawString("Option 1", font, brush2, New PointF(baseX + 20, baseY))
 
            Dim radioItem2 As PdfRadioButtonListItem =  New PdfRadioButtonListItem("option2") 
            Dim radioBound2 As RectangleF =  New RectangleF(baseX + 70,baseY,15,15) 
            radioItem2.Bounds = radioBound2
            page.Canvas.DrawString("Option 2", font, brush2, New PointF(baseX + 90, baseY))
            radioButtonListField.Items.Add(radioItem1)
            radioButtonListField.Items.Add(radioItem2)
            radioButtonListField.SelectedIndex = 0
            doc.Form.Fields.Add(radioButtonListField)
            baseY += 25
 
            'Add a combobox
            page.Canvas.DrawString("ComboBox:",font,brush1,New PointF(10,baseY))
            Dim cmbBounds As RectangleF =  New RectangleF(baseX,baseY,150,15) 
            Dim comboBoxField As PdfComboBoxField =  New PdfComboBoxField(page,"combobox") 
            comboBoxField.Bounds = cmbBounds
            comboBoxField.Items.Add(New PdfListFieldItem("Item 1","item1"))
            comboBoxField.Items.Add(New PdfListFieldItem("Item 2","itme2"))
            comboBoxField.Items.Add(New PdfListFieldItem("Item 3","item3"))
            comboBoxField.Items.Add(New PdfListFieldItem("Item 4","item4"))
            comboBoxField.SelectedIndex = 0
            comboBoxField.Font = font
            doc.Form.Fields.Add(comboBoxField)
            baseY += 25
 
            'Add a signature field
            page.Canvas.DrawString("Signature Field:",font,brush1,New PointF(10,baseY))
            Dim sgnField As PdfSignatureField =  New PdfSignatureField(page,"sgnField") 
            Dim sgnBounds As RectangleF =  New RectangleF(baseX,baseY,150,80) 
            sgnField.Bounds = sgnBounds
            doc.Form.Fields.Add(sgnField)
            baseY += 90
 
            'Add a button
            page.Canvas.DrawString("Button:",font,brush1,New PointF(10,baseY))
            Dim btnBounds As RectangleF =  New RectangleF(baseX,baseY,50,15) 
            Dim buttonField As PdfButtonField =  New PdfButtonField(page,"button") 
            buttonField.Bounds = btnBounds
            buttonField.Text = "Submit"
            buttonField.Font = font
            Dim submitAction As PdfSubmitAction =  New PdfSubmitAction("https://www.e-iceblue.com/getformvalues.php") 
            submitAction.DataFormat = SubmitDataFormat.Html
            buttonField.Actions.MouseDown = submitAction
            doc.Form.Fields.Add(buttonField)
 
            'Save to file
            doc.SaveToFile("FillableForms.pdf", FileFormat.PDF)
        End Sub
    End Class
End Namespace

using Spire.Pdf;
using Spire.Pdf.Fields;
using Spire.Pdf.Widget;

namespace FillFormFields
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a PdfDocument object
            PdfDocument doc = new PdfDocument();

            //Load a template containing forms
            doc.LoadFromFile(@"C:\Users\Administrator\Desktop\FormsTemplate.pdf");

            //Get the form from the document
            PdfFormWidget form = (PdfFormWidget)doc.Form;

            //Get the form widget collection
            PdfFormFieldWidgetCollection formWidgetCollection = form.FieldsWidget;

            //Loop through the widgets
            for (int i = 0; i < formWidgetCollection.Count; i++)
            {
                //Get a specific field
                PdfField field = formWidgetCollection[i];

                //Determine if the field is a text box
                if (field is PdfTextBoxFieldWidget)
                {
                    if (field.Name == "name")
                    {
                        //Set the text of text box
                        PdfTextBoxFieldWidget textBoxField = (PdfTextBoxFieldWidget)field;
                        textBoxField.Text = "Kaila Smith";
                    }
                }

                //Determine if the field is a radio button
                if (field is PdfRadioButtonListFieldWidget)
                {
                    if (field.Name == "gender")
                    {
                        //Set the selected index of radio button
                        PdfRadioButtonListFieldWidget radioButtonListField = (PdfRadioButtonListFieldWidget)field;
                        radioButtonListField.SelectedIndex = 1;
                    }
                }

                //Determine if the field is a combo box
                if (field is PdfComboBoxWidgetFieldWidget)
                {
                    if (field.Name == "country")
                    {
                        //Set the selected index of combo box
                        PdfComboBoxWidgetFieldWidget comboBoxField = (PdfComboBoxWidgetFieldWidget)field;
                        int[] index = { 0 };
                        comboBoxField.SelectedIndex = index;
                    }
                }

                //Determine if the field is a check box
                if (field is PdfCheckBoxWidgetFieldWidget)
                {
                    //Set the "Checked" status of check box
                    PdfCheckBoxWidgetFieldWidget checkBoxField = (PdfCheckBoxWidgetFieldWidget)field;
                    switch (checkBoxField.Name)
                    {
                        case "travel":
                            checkBoxField.Checked = true;
                            break;
                        case "movie":
                            checkBoxField.Checked = true;
                            break;
                    }
                }

                //Determine if the field is a list box
                if (field is PdfListBoxWidgetFieldWidget)
                {
                    if (field.Name == "degree")
                    {
                        //Set the selected index of list box
                        PdfListBoxWidgetFieldWidget listBox = (PdfListBoxWidgetFieldWidget)field;
                        int[] index = { 1 };
                        listBox.SelectedIndex = index;
                    }
                }
            }

            //Save to file
            doc.SaveToFile("FillFormFields.pdf", FileFormat.PDF);
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Fields
Imports Spire.Pdf.Widget
 
Namespace FillFormFields
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument() 
 
            'Load a template containing forms
            doc.LoadFromFile("C:\Users\Administrator\Desktop\FormsTemplate.pdf")
 
            'Get the form fields from the document
            Dim form As PdfFormWidget = CType(doc.Form, PdfFormWidget)
 
            'Get the form widget collection
            Dim formWidgetCollection As PdfFormFieldWidgetCollection =  form.FieldsWidget 
 
            'Loop through the widgets
            Dim i As Integer
            For  i = 0 To  formWidgetCollection.Count- 1  Step  i + 1
                'Get a specific field
                Dim field As PdfField =  formWidgetCollection(i) 
 
                'Determine if the field is a text box
                If TypeOf field Is PdfTextBoxFieldWidget Then
                    If field.Name = "name" Then
                        'Set the text of text box
                        Dim textBoxField As PdfTextBoxFieldWidget = CType(field, PdfTextBoxFieldWidget)
                        textBoxField.Text = "Kaila Smith"
                    End If
                End If
 
                'Determine if the field is a radio button
                If TypeOf field Is PdfRadioButtonListFieldWidget Then
                    If field.Name = "gender" Then
                        'Set the selected index of radio button
                        Dim radioButtonListField As PdfRadioButtonListFieldWidget = CType(field, PdfRadioButtonListFieldWidget)
                        radioButtonListField.SelectedIndex = 1
                    End If
                End If
 
                'Determine if the field is a combo box
                If TypeOf field Is PdfComboBoxWidgetFieldWidget Then
                    If field.Name = "country" Then
                        'Set the selected index of combo box
                        Dim comboBoxField As PdfComboBoxWidgetFieldWidget = CType(field, PdfComboBoxWidgetFieldWidget)
                        Dim index() As Integer = {0}

                        comboBoxField.SelectedIndex = index
                    End If
                End If
 
                'Determine if the field is a check box
                If TypeOf field Is PdfCheckBoxWidgetFieldWidget Then
                    'Set the "Checked" status of check box
                    Dim checkBoxField As PdfCheckBoxWidgetFieldWidget = CType(field, PdfCheckBoxWidgetFieldWidget)
                    Select Case checkBoxField.Name
                        Case "travel"
                            checkBoxField.Checked = True
                            Exit For
                        Case "movie"
                            checkBoxField.Checked = True
                            Exit For
                    End Select
                End If
 
                'Determine if the field is a list box
                If TypeOf field Is PdfListBoxWidgetFieldWidget Then
                    If field.Name = "degree" Then
                        'Set the selected index of list box
                        Dim listBox As PdfListBoxWidgetFieldWidget = CType(field, PdfListBoxWidgetFieldWidget)
                        Dim index() As Integer = {1}

                        listBox.SelectedIndex = index
                    End If
                End If
            Next
 
            'Save to file
            doc.SaveToFile("FillFormFields.pdf", FileFormat.PDF)
        End Sub
    End Class
End Namespace

using Spire.Pdf;
using Spire.Pdf.Fields;
using Spire.Pdf.Widget;

namespace RemoveFormFields
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a PdfDocument object
            PdfDocument doc = new PdfDocument();

            //Load a PDF file
            doc.LoadFromFile(@"C:\Users\Administrator\Desktop\FormsTemplate.pdf");

            //Get the form fields from the document
            PdfFormWidget formWidget = doc.Form as PdfFormWidget;

            //Loop through the widgets
            for (int i = formWidget.FieldsWidget.List.Count - 1; i >= 0; i--)
            {
                //Get a specific field
                PdfField field = formWidget.FieldsWidget.List[i] as PdfField;

                //Remove the field
                formWidget.FieldsWidget.Remove(field);
            }

            //Get a specific field by its name
            //PdfField field = formWidget.FieldsWidget["name"];
            //Remove the field
            //formWidget.FieldsWidget.Remove(field);

            //Save to file
            doc.SaveToFile("DeleteAllFields.pdf");
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Fields
Imports Spire.Pdf.Widget
 
Namespace RemoveFormFields
    Class Program
        static void Main(string() args)
        {
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument() 
 
            'Load a PDF file
            doc.LoadFromFile("C:\Users\Administrator\Desktop\FormsTemplate.pdf")
 
            'Get the form fields from the document
            Dim formWidget As PdfFormWidget =  doc.Form as PdfFormWidget 
 
            'Loop through the widgets
            for(Integer i  =  formWidget.FieldsWidget.List.Count - 1 i > =  0 i--)
            {
                'Get a specific field
                Dim field As PdfField =  formWidget.FieldsWidget.List(i) as PdfField 
 
                'Remove the field
                formWidget.FieldsWidget.Remove(field)
            }
 
            'Get a specific field by its name
            'PdfField field = formWidget.FieldsWidget["name"];
            'Remove the field
            'formWidget.FieldsWidget.Remove(field);
 
            'Save to file
            doc.SaveToFile("DeleteAllFields.pdf")
        }
    End Class
End Namespace