static void Main(string[] args)
        {
            PDFNet.Initialize();

            // Relative path to the folder containing test files.
            // string input_path =  "../../TestFiles/";
            string output_path = "../../TestFiles/Output/";

            // The vector used to store the name and count of all fields.
            // This is used later on to clone the fields
            Dictionary <string, int> field_names = new Dictionary <string, int>();

            //----------------------------------------------------------------------------------
            // Example 1: Programatically create new Form Fields and Widget Annotations.
            //----------------------------------------------------------------------------------
            try
            {
                using (PDFDoc doc = new PDFDoc())
                {
                    // Create a blank new page and add some form fields.
                    Page blank_page = doc.PageCreate();

                    // Text Widget Creation
                    // Create an empty text widget with black text.
                    TextWidget text1 = TextWidget.Create(doc, new Rect(110, 700, 380, 730));
                    text1.SetText("Basic Text Field");
                    text1.RefreshAppearance();
                    blank_page.AnnotPushBack(text1);
                    // Create a vertical text widget with blue text and a yellow background.
                    TextWidget text2 = TextWidget.Create(doc, new Rect(50, 400, 90, 730));
                    text2.SetRotation(90);
                    // Set the text content.
                    text2.SetText("    ****Lucky Stars!****");
                    // Set the font type, text color, font size, border color and background color.
                    text2.SetFont(Font.Create(doc, Font.StandardType1Font.e_helvetica_oblique));
                    text2.SetFontSize(28);
                    text2.SetTextColor(new ColorPt(0, 0, 1), 3);
                    text2.SetBorderColor(new ColorPt(0, 0, 0), 3);
                    text2.SetBackgroundColor(new ColorPt(1, 1, 0), 3);
                    text2.RefreshAppearance();
                    // Add the annotation to the page.
                    blank_page.AnnotPushBack(text2);
                    // Create two new text widget with Field names employee.name.first and employee.name.last
                    // This logic shows how these widgets can be created using either a field name string or
                    // a Field object
                    TextWidget text3 = TextWidget.Create(doc, new Rect(110, 660, 380, 690), "employee.name.first");
                    text3.SetText("Levi");
                    text3.SetFont(Font.Create(doc, Font.StandardType1Font.e_times_bold));
                    text3.RefreshAppearance();
                    blank_page.AnnotPushBack(text3);
                    Field      emp_last_name = doc.FieldCreate("employee.name.last", Field.Type.e_text, "Ackerman");
                    TextWidget text4         = TextWidget.Create(doc, new Rect(110, 620, 380, 650), emp_last_name);
                    text4.SetFont(Font.Create(doc, Font.StandardType1Font.e_times_bold));
                    text4.RefreshAppearance();
                    blank_page.AnnotPushBack(text4);

                    // Signature Widget Creation (unsigned)
                    SignatureWidget signature1 = SignatureWidget.Create(doc, new Rect(110, 560, 260, 610));
                    signature1.RefreshAppearance();
                    blank_page.AnnotPushBack(signature1);

                    // CheckBox Widget Creation
                    // Create a check box widget that is not checked.
                    CheckBoxWidget check1 = CheckBoxWidget.Create(doc, new Rect(140, 490, 170, 520));
                    check1.RefreshAppearance();
                    blank_page.AnnotPushBack(check1);
                    // Create a check box widget that is checked.
                    CheckBoxWidget check2 = CheckBoxWidget.Create(doc, new Rect(190, 490, 250, 540), "employee.name.check1");
                    check2.SetBackgroundColor(new ColorPt(1, 1, 1), 3);
                    check2.SetBorderColor(new ColorPt(0, 0, 0), 3);
                    // Check the widget (by default it is unchecked).
                    check2.SetChecked(true);
                    check2.RefreshAppearance();
                    blank_page.AnnotPushBack(check2);

                    // PushButton Widget Creation
                    PushButtonWidget pushbutton1 = PushButtonWidget.Create(doc, new Rect(380, 490, 520, 540));
                    pushbutton1.SetTextColor(new ColorPt(1, 1, 1), 3);
                    pushbutton1.SetFontSize(36);
                    pushbutton1.SetBackgroundColor(new ColorPt(0, 0, 0), 3);
                    // Add a caption for the pushbutton.
                    pushbutton1.SetStaticCaptionText("PushButton");
                    pushbutton1.RefreshAppearance();
                    blank_page.AnnotPushBack(pushbutton1);

                    // ComboBox Widget Creation
                    ComboBoxWidget combo1 = ComboBoxWidget.Create(doc, new Rect(280, 560, 580, 610));
                    // Add options to the combobox widget.
                    combo1.AddOption("Combo Box No.1");
                    combo1.AddOption("Combo Box No.2");
                    combo1.AddOption("Combo Box No.3");
                    // Make one of the options in the combo box selected by default.
                    combo1.SetSelectedOption("Combo Box No.2");
                    combo1.SetTextColor(new ColorPt(1, 0, 0), 3);
                    combo1.SetFontSize(28);
                    combo1.RefreshAppearance();
                    blank_page.AnnotPushBack(combo1);

                    // ListBox Widget Creation
                    ListBoxWidget list1 = ListBoxWidget.Create(doc, new Rect(400, 620, 580, 730));
                    // Add one option to the listbox widget.
                    list1.AddOption("List Box No.1");
                    // Add multiple options to the listbox widget in a batch.
                    string[] list_options = new string[2] {
                        "List Box No.2", "List Box No.3"
                    };
                    list1.AddOptions(list_options);
                    // Select some of the options in list box as default options
                    list1.SetSelectedOptions(list_options);
                    // Enable list box to have multi-select when editing.
                    list1.GetField().SetFlag(Field.Flag.e_multiselect, true);
                    list1.SetFont(Font.Create(doc, Font.StandardType1Font.e_times_italic));
                    list1.SetTextColor(new ColorPt(1, 0, 0), 3);
                    list1.SetFontSize(28);
                    list1.SetBackgroundColor(new ColorPt(1, 1, 1), 3);
                    list1.RefreshAppearance();
                    blank_page.AnnotPushBack(list1);

                    // RadioButton Widget Creation
                    // Create a radio button group and add three radio buttons in it.
                    RadioButtonGroup  radio_group  = RadioButtonGroup.Create(doc, "RadioGroup");
                    RadioButtonWidget radiobutton1 = radio_group.Add(new Rect(140, 410, 190, 460));
                    radiobutton1.SetBackgroundColor(new ColorPt(1, 1, 0), 3);
                    radiobutton1.RefreshAppearance();
                    RadioButtonWidget radiobutton2 = radio_group.Add(new Rect(310, 410, 360, 460));
                    radiobutton2.SetBackgroundColor(new ColorPt(0, 1, 0), 3);
                    radiobutton2.RefreshAppearance();
                    RadioButtonWidget radiobutton3 = radio_group.Add(new Rect(480, 410, 530, 460));
                    // Enable the third radio button. By default the first one is selected
                    radiobutton3.EnableButton();
                    radiobutton3.SetBackgroundColor(new ColorPt(0, 1, 1), 3);
                    radiobutton3.RefreshAppearance();
                    radio_group.AddGroupButtonsToPage(blank_page);

                    // Custom push button annotation creation
                    PushButtonWidget custom_pushbutton1 = PushButtonWidget.Create(doc, new Rect(260, 320, 360, 360));
                    // Set the annotation appearance.
                    custom_pushbutton1.SetAppearance(CreateCustomButtonAppearance(doc, false), Annot.AnnotationState.e_normal);
                    // Create 'SubmitForm' action. The action will be linked to the button.
                    FileSpec           url           = FileSpec.CreateURL(doc, "http://www.pdftron.com");
                    pdftron.PDF.Action button_action = pdftron.PDF.Action.CreateSubmitForm(url);
                    // Associate the above action with 'Down' event in annotations action dictionary.
                    Obj annot_action = custom_pushbutton1.GetSDFObj().PutDict("AA");
                    annot_action.Put("D", button_action.GetSDFObj());
                    blank_page.AnnotPushBack(custom_pushbutton1);

                    // Add the page as the last page in the document.
                    doc.PagePushBack(blank_page);

                    // If you are not satisfied with the look of default auto-generated appearance
                    // streams you can delete "AP" entry from the Widget annotation and set
                    // "NeedAppearances" flag in AcroForm dictionary:
                    //    doc.GetAcroForm().PutBool("NeedAppearances", true);
                    // This will force the viewer application to auto-generate new appearance streams
                    // every time the document is opened.
                    //
                    // Alternatively you can generate custom annotation appearance using ElementWriter
                    // and then set the "AP" entry in the widget dictionary to the new appearance
                    // stream.
                    //
                    // Yet another option is to pre-populate field entries with dummy text. When
                    // you edit the field values using PDFNet the new field appearances will match
                    // the old ones.
                    doc.RefreshFieldAppearances();

                    doc.Save(output_path + "forms_test1.pdf", 0);

                    Console.WriteLine("Done.");
                }
            }
            catch (PDFNetException e)
            {
                Console.WriteLine(e.Message);
            }

            //----------------------------------------------------------------------------------
            // Example 2:
            // Fill-in forms / Modify values of existing fields.
            // Traverse all form fields in the document (and print out their names).
            // Search for specific fields in the document.
            //----------------------------------------------------------------------------------
            try
            {
                using (PDFDoc doc = new PDFDoc(output_path + "forms_test1.pdf"))
                {
                    doc.InitSecurityHandler();

                    FieldIterator itr;
                    for (itr = doc.GetFieldIterator(); itr.HasNext(); itr.Next())
                    {
                        Field  field          = itr.Current();
                        string cur_field_name = field.GetName();
                        // Add one to the count for this field name for later processing
                        field_names[cur_field_name] = (field_names.ContainsKey(cur_field_name) ? field_names[cur_field_name] + 1 : 1);

                        Console.WriteLine("Field name: {0}", field.GetName());
                        Console.WriteLine("Field partial name: {0}", field.GetPartialName());
                        string str_val = field.GetValueAsString();

                        Console.Write("Field type: ");
                        Field.Type type = field.GetType();
                        switch (type)
                        {
                        case Field.Type.e_button:
                            Console.WriteLine("Button");
                            break;

                        case Field.Type.e_radio:
                            Console.WriteLine("Radio button: Value = " + str_val);
                            break;

                        case Field.Type.e_check:
                            field.SetValue(true);
                            Console.WriteLine("Check box: Value = " + str_val);
                            break;

                        case Field.Type.e_text:
                        {
                            Console.WriteLine("Text");

                            // Edit all variable text in the document
                            String old_value = "none";
                            if (field.GetValue() != null)
                            {
                                old_value = field.GetValue().GetAsPDFText();
                            }

                            field.SetValue("This is a new value. The old one was: " + old_value);
                        }
                        break;

                        case Field.Type.e_choice:
                            Console.WriteLine("Choice");
                            break;

                        case Field.Type.e_signature:
                            Console.WriteLine("Signature");
                            break;
                        }

                        Console.WriteLine("------------------------------");
                    }

                    // Search for a specific field
                    Field fld = doc.GetField("employee.name.first");
                    if (fld != null)
                    {
                        Console.WriteLine("Field search for {0} was successful", fld.GetName());
                    }
                    else
                    {
                        Console.WriteLine("Field search failed.");
                    }

                    // Regenerate field appearances.
                    doc.RefreshFieldAppearances();
                    doc.Save(output_path + "forms_test_edit.pdf", 0);
                    Console.WriteLine("Done.");
                }
            }
            catch (PDFNetException e)
            {
                Console.WriteLine(e.Message);
            }

            //----------------------------------------------------------------------------------
            // Sample: Form templating
            // Replicate pages and form data within a document. Then rename field names to make
            // them unique.
            //----------------------------------------------------------------------------------
            try
            {
                // Sample: Copying the page with forms within the same document
                using (PDFDoc doc = new PDFDoc(output_path + "forms_test1.pdf"))
                {
                    doc.InitSecurityHandler();

                    Page src_page = doc.GetPage(1);
                    doc.PagePushBack(src_page);                      // Append several copies of the second page
                    doc.PagePushBack(src_page);                      // Note that forms are successfully copied
                    doc.PagePushBack(src_page);
                    doc.PagePushBack(src_page);

                    // Now we rename fields in order to make every field unique.
                    // You can use this technique for dynamic template filling where you have a 'master'
                    // form page that should be replicated, but with unique field names on every page.
                    foreach (KeyValuePair <string, int> cur_field in field_names)
                    {
                        RenameAllFields(doc, cur_field.Key, cur_field.Value);
                    }

                    doc.Save(output_path + "forms_test1_cloned.pdf", 0);
                    Console.WriteLine("Done.");
                }
            }
            catch (PDFNetException e)
            {
                Console.WriteLine(e.Message);
            }

            //----------------------------------------------------------------------------------
            // Sample:
            // Flatten all form fields in a document.
            // Note that this sample is intended to show that it is possible to flatten
            // individual fields. PDFNet provides a utility function PDFDoc.FlattenAnnotations()
            // that will automatically flatten all fields.
            //----------------------------------------------------------------------------------
            try
            {
                using (PDFDoc doc = new PDFDoc(output_path + "forms_test1.pdf"))
                {
                    doc.InitSecurityHandler();

                    bool auto = true;
                    if (auto)
                    {
                        doc.FlattenAnnotations();
                    }
                    else                      // Manual flattening
                    {
                        // Traverse all pages
                        PageIterator pitr = doc.GetPageIterator();
                        for (; pitr.HasNext(); pitr.Next())
                        {
                            Page page = pitr.Current();
                            for (int i = page.GetNumAnnots() - 1; i >= 0; --i)
                            {
                                Annot annot = page.GetAnnot(i);
                                if (annot.GetType() == Annot.Type.e_Widget)
                                {
                                    annot.Flatten(page);
                                }
                            }
                        }
                    }

                    doc.Save(output_path + "forms_test1_flattened.pdf", 0);
                    Console.WriteLine("Done.");
                }
            }
            catch (PDFNetException e)
            {
                Console.WriteLine(e.Message);
            }
        }