PM> Install-Package Spire.PDF

using Spire.Pdf;
using Spire.Pdf.Attachments;

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

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

            //Create a PdfAttachment object based on an external file
            PdfAttachment attachment = new PdfAttachment("C:\\Users\\Administrator\\Desktop\\Data.xlsx");

            //Add the attachment to PDF
            doc.Attachments.Add(attachment);

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

Imports Spire.Pdf
Imports Spire.Pdf.Attachments
 
Namespace AttachFilesToPDF
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument() 
 
            'Load a sample PDF file
            doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Sample.pdf")
 
            'Create a PdfAttachment object based on an external file
            Dim attachment As PdfAttachment =  New PdfAttachment("C:\\Users\\Administrator\\Desktop\\Data.xlsx") 
 
            'Add the attachment to PDF
            doc.Attachments.Add(attachment)
 
            'Save to file
            doc.SaveToFile("Attachment.pdf")
        End Sub
    End Class
End Namespace

using Spire.Pdf;
using Spire.Pdf.Annotations;
using Spire.Pdf.Graphics;
using System;
using System.Drawing;
using System.IO;

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

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

            //Get a specific page
            PdfPageBase page = doc.Pages[0];

            //Draw a label on PDF
            String label = "Here is the report:";
            PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Arial", 13f, FontStyle.Bold), true); 
            float x = 35;
            float y = doc.Pages[0].ActualSize.Height - 220;
            page.Canvas.DrawString(label, font, PdfBrushes.Red, x, y);

            //Create a PdfAttachmentAnnotation object based on an external file
            String filePath = "C:\\Users\\Administrator\\Desktop\\Report.pptx";
            byte[] data = File.ReadAllBytes(filePath);
            SizeF size = font.MeasureString(label);
            RectangleF bounds = new RectangleF((float)(x + size.Width + 5), (float)y, 10, 15);
            PdfAttachmentAnnotation annotation = new PdfAttachmentAnnotation(bounds, "Report.docx", data);
            annotation.Color = Color.Purple;
            annotation.Flags = PdfAnnotationFlags.Default;
            annotation.Icon = PdfAttachmentIcon.Graph;
            annotation.Text = "Click here to open the file";

            //Add the attachment annotation to PDF
            page.AnnotationsWidget.Add(annotation);

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

Imports Spire.Pdf
Imports Spire.Pdf.Annotations
Imports Spire.Pdf.Graphics
Imports System
Imports System.Drawing
Imports System.IO
 
Namespace AnnotationAttachment
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument() 
 
            'Load a sample PDF file
            doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Sample.pdf")
 
            'Get a specific page
            Dim page As PdfPageBase =  doc.Pages(0) 
 
            'Draw a label on PDF
            Dim label As String =  "Here is the report:" 
            Dim font As PdfTrueTypeFont =  New PdfTrueTypeFont(New Font("Arial",13f,FontStyle.Bold),True) 
            Dim x As single =  35 
            Dim y As single =  doc.Pages(0).ActualSize.Height - 220 
            page.Canvas.DrawString(label, font, PdfBrushes.Red, x, y)
 
            'Create a PdfAttachmentAnnotation object based on an external file
            Dim filePath As String =  "C:\\Users\\Administrator\\Desktop\\Report.pptx" 
            Dim data() As Byte =  File.ReadAllBytes(filePath) 
            Dim size As SizeF =  font.MeasureString(label) 
            Dim bounds As RectangleF =  New RectangleF(CType((x + size.Width + 5),(single)y,10,15, single)) 
            Dim annotation As PdfAttachmentAnnotation =  New PdfAttachmentAnnotation(bounds,"Report.docx",data) 
            annotation.Color = Color.Purple
            annotation.Flags = PdfAnnotationFlags.Default
            annotation.Icon = PdfAttachmentIcon.Graph
            annotation.Text = "Click here to open the file"
 
            'Add the attachment annotation to PDF
            page.AnnotationsWidget.Add(annotation)
 
            'Save to file
            doc.SaveToFile("Annotation.pdf")
        End Sub
    End Class
End Namespace

using Spire.Pdf;
using Spire.Pdf.Attachments;

namespace RemoveAttachments
{
    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\\Attachment.pdf");

            //Get attachment collection
            PdfAttachmentCollection attachments = doc.Attachments;

            //Remove a specific attachment
            attachments.RemoveAt(0);

            //Remove all attachments
            //attachments.Clear();

            //save to file
            doc.SaveToFile("DeleteAttachments.pdf");
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Attachments
 
Namespace RemoveAttachments
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument() 
 
            'Load a PDF file
            doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Attachment.pdf")
 
            'Get attachment collection
            Dim attachments As PdfAttachmentCollection =  doc.Attachments 
 
            'Remove a specific attachment
            attachments.RemoveAt(0)
 
            'Remove all attachments
            'attachments.Clear();
 
            'save to file
            doc.SaveToFile("DeleteAttachments.pdf")
        End Sub
    End Class
End Namespace

using Spire.Pdf;
using Spire.Pdf.Annotations;

namespace RemoveAnnotationAttachments
{
    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\\Annotation.pdf");

            //Loop through the pages
            for (int i = 0; i < doc.Pages.Count; i++)
            {
                //Get the annotation collection
                PdfAnnotationCollection annotationCollection = doc.Pages[i].AnnotationsWidget;

                //Loop through the annotations
                for (int j = 0; j < annotationCollection.Count; j++)
                {
                    //Determine if an annotation is an instance of PdfAttachmentAnnotationWidget
                    if (annotationCollection[j] is PdfAttachmentAnnotationWidget)
                    {
                        //Remove the annotation attachment 
                        annotationCollection.Remove((PdfAnnotation)annotationCollection[j]);
                    }
                }
            }

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

Imports Spire.Pdf
Imports Spire.Pdf.Annotations
 
Namespace RemoveAnnotationAttachments
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument() 
 
            'Load a PDF file
            doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Annotation.pdf")
 
            'Loop through the pages
            Dim i As Integer
            For  i = 0 To  doc.Pages.Count- 1  Step  i + 1
                'Get the annotation collection
                Dim annotationCollection As PdfAnnotationCollection =  doc.Pages(i).AnnotationsWidget 
 
                'Loop through the annotations
                Dim j As Integer
                For  j = 0 To  annotationCollection.Count- 1  Step  j + 1
                    'Determine if an annotation is an instance of PdfAttachmentAnnotationWidget
                    If TypeOf annotationCollection(j) Is PdfAttachmentAnnotationWidget Then
                        'Remove the annotation attachment 
                        annotationCollection.Remove(CType(annotationCollection(j), PdfAnnotation))
                    End If
                Next
            Next
 
            'Save to file
            doc.SaveToFile("DeleteAnnotationAttachments.pdf")
        End Sub
    End Class
End Namespace

PM> Install-Package Spire.PDF

using System;
using Spire.Pdf;
using Spire.Pdf.Graphics;
using Spire.Pdf.Lists;

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

            //Set the margins
            PdfMargins margins = new PdfMargins(30);

            //Add a page
            PdfPageBase page = doc.Pages.Add(PdfPageSize.A4, margins);

            //Create a brush
            PdfBrush brush = PdfBrushes.Black;

            //Create fonts
            PdfFont titleFont = new PdfFont(PdfFontFamily.TimesRoman, 12f, PdfFontStyle.Bold);
            PdfFont listFont = new PdfFont(PdfFontFamily.TimesRoman, 12f, PdfFontStyle.Regular);

            //Create a maker for ordered list
            PdfOrderedMarker marker = new PdfOrderedMarker(PdfNumberStyle.LowerLatin, listFont);

            //Specify the initial coordinate
            float x = 10;
            float y = 20;

            //Draw title
            String title = "Required Web Development Skills:";
            page.Canvas.DrawString(title, titleFont, brush, x, y);
            y = y + (float)titleFont.MeasureString(title).Height;
            y = y + 5;


            //Create a numbered list
            String listContent = "Command-line Unix\n"
                + "Vim\n"
                + "HTML\n"
                + "CSS\n"
                + "Python\n"
                + "JavaScript\n"
                + "SQL";
            PdfSortedList list = new PdfSortedList(listContent);

            //Set the font, indent, text indent, brush of the list
            list.Font = listFont;
            list.Indent = 2;
            list.TextIndent = 4;
            list.Brush = brush;
            list.Marker = marker;

            //Draw list on the page at the specified location
            list.Draw(page, x, y);

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

Imports System
Imports Spire.Pdf
Imports Spire.Pdf.Graphics
Imports Spire.Pdf.Lists

Namespace CreateOrderedList
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument()

            'Set the margins
            Dim margins As PdfMargins =  New PdfMargins(30)

            'Add a page
            Dim page As PdfPageBase =  doc.Pages.Add(PdfPageSize.A4,margins)

            'Create a brush
            Dim brush As PdfBrush =  PdfBrushes.Black

            'Create fonts
            Dim titleFont As PdfFont =  New PdfFont(PdfFontFamily.TimesRoman,12f,PdfFontStyle.Bold)
            Dim listFont As PdfFont =  New PdfFont(PdfFontFamily.TimesRoman,12f,PdfFontStyle.Regular)

            'Create a maker for ordered list
            Dim marker As PdfOrderedMarker =  New PdfOrderedMarker(PdfNumberStyle.LowerLatin,listFont)

            'Specify the initial coordinate
            Dim x As single =  10
            Dim y As single =  20

            'Draw title
            Dim title As String =  "Required Web Development Skills:"
            page.Canvas.DrawString(title, titleFont, brush, x, y)
            y = y + CType(titleFont.MeasureString(title).Height, single)
            y = y + 5

            Create a numbered list
            Dim listContent As String = "Command-line Unix" & vbCrLf & _
            "Vim" & vbCrLf & _
            "HTML" & vbCrLf & _
            "CSS" & vbCrLf & _
            "Python" & vbCrLf & _
            "JavaScript" & vbCrLf & _
            "SQL"

            Dim list As PdfSortedList = New PdfSortedList(listContent)

            'Set the font, indent, text indent, brush of the list
            list.Font = listFont
            list.Indent = 2
            list.TextIndent = 4
            list.Brush = brush
            list.Marker = marker

            'Draw list on the page at the specified location
            list.Draw(page, x, y)

            'Save to file
            doc.SaveToFile("OrderedList.pdf")
        End Sub
    End Class
End Namespace

using Spire.Pdf;
using Spire.Pdf.Graphics;
using Spire.Pdf.Lists;
using System;

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

            //Set the margin
            PdfMargins margin = new PdfMargins(30);

            //Add a page
            PdfPageBase page = doc.Pages.Add(PdfPageSize.A4, margin);

            //Create fonts
            PdfFont titleFont = new PdfFont(PdfFontFamily.TimesRoman, 12f, PdfFontStyle.Bold);
            PdfFont listFont = new PdfFont(PdfFontFamily.TimesRoman, 12f, PdfFontStyle.Regular);
            PdfFont markerFont = new PdfFont(PdfFontFamily.TimesRoman, 6f, PdfFontStyle.Regular);

            //Create a brush
            PdfBrush brush = PdfBrushes.Black;

            //Specify the initial coordinate
            float x = 10;
            float y = 20;

            //Draw title
            String title = "Computer Science Subjects:";
            page.Canvas.DrawString(title, titleFont, brush, x, y);
            y = y + (float)titleFont.MeasureString(title).Height;
            y = y + 5;

            //Specify the marker style
            PdfMarker marker = new PdfMarker(PdfUnorderedMarkerStyle.Asterisk);
            marker.Font = markerFont;

            //Create an unordered list
            String listContent = "Data Structure\n"
                    + "Algorithm\n"
                    + "Computer Networks\n"
                    + "Operating System\n"
                    + "Theory of Computations\n"
                    + "C Programming\n"
                    +"Computer Organization and Architecture";

            PdfList list = new PdfList(listContent);

            //Set the font, indent, text indent, brush, maker of the list
            list.Font = listFont;
            list.Indent = 2;
            list.TextIndent = 4;
            list.Brush = brush;
            list.Marker = marker;

            //Draw list on a page at the specified location
            list.Draw(page, x, y);

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

Imports Spire.Pdf
Imports Spire.Pdf.Graphics
Imports Spire.Pdf.Lists
Imports System

Namespace CreateBulletedList
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument()

            'Set the margin
            Dim margin As PdfMargins =  New PdfMargins(30)

            'Add a page
            Dim page As PdfPageBase =  doc.Pages.Add(PdfPageSize.A4,margin)

            'Create fonts
            Dim titleFont As PdfFont =  New PdfFont(PdfFontFamily.TimesRoman,12f,PdfFontStyle.Bold)
            Dim listFont As PdfFont =  New PdfFont(PdfFontFamily.TimesRoman,12f,PdfFontStyle.Regular)
            Dim markerFont As PdfFont =  New PdfFont(PdfFontFamily.TimesRoman,6f,PdfFontStyle.Regular)

            'Create a brush
            Dim brush As PdfBrush =  PdfBrushes.Black

            'Specify the initial coordinate
            Dim x As single =  10
            Dim y As single =  20

            'Draw title
            Dim title As String =  "Computer Science Subjects:"
            page.Canvas.DrawString(title, titleFont, brush, x, y)
            y = y + CType(titleFont.MeasureString(title).Height, single)
            y = y + 5

            'Specify the marker style
            Dim marker As PdfMarker =  New PdfMarker(PdfUnorderedMarkerStyle.Asterisk)
            marker.Font = markerFont

            'Create an unordered list
            String listContent = "Data Structure\n"
                    + "Algorithm\n"
                    + "Computer Networks\n"
                    + "Operating System\n"
                    + "Theory of Computations\n"
                    + "C Programming\n"
                    +"Computer Organization and Architecture"

            Dim list As PdfList =  New PdfList(listContent)

            'Set the font, indent, text indent, brush, maker of the list
            list.Font = listFont
            list.Indent = 2
            list.TextIndent = 4
            list.Brush = brush
            list.Marker = marker

            'Draw list on a page at the specified location
            list.Draw(page, x, y)

            'Save to file
            doc.SaveToFile("UnorderedList.pdf")
        End Sub
    End Class
End Namespace

using System;
using Spire.Pdf;
using Spire.Pdf.Graphics;
using Spire.Pdf.Lists;

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

            //Set the margin
            PdfMargins margin = new PdfMargins(30);

            //Add a page
            PdfPageBase page = doc.Pages.Add(PdfPageSize.A4, margin);

            //Create fonts
            PdfFont titleFont = new PdfFont(PdfFontFamily.TimesRoman, 12f, PdfFontStyle.Bold);
            PdfFont listFont = new PdfFont(PdfFontFamily.TimesRoman, 12f, PdfFontStyle.Regular);

            //Create a brush
            PdfBrush brush = PdfBrushes.Black;

            //Specify the initial coordinate
            float x = 10;
            float y = 20;

            //Draw title
            String title = "Project Task To-Do List:";
            page.Canvas.DrawString(title, titleFont, brush, x, y);
            y = y + (float)titleFont.MeasureString(title).Height;
            y = y + 5;

            //Specify the marker style to image
            PdfMarker marker = new PdfMarker(PdfUnorderedMarkerStyle.CustomImage);

            //Set the image for the marker
            marker.Image = PdfImage.FromFile(@"C:\Users\Administrator\Desktop\checkmark.jpg");

            //Create an unordered list
            String listContent = "Define projects and tasks you're working on\n"
                    + "Assign people to tasks\n"
                    + "Define the priority levels of your tasks\n"
                    + "Keep track of the progress status of your tasks\n"
                    + "Mark tasks as done when completed";
            PdfList list = new PdfList(listContent);

            //Set the font, indent, text indent, brush, maker of the list
            list.Font = listFont;
            list.Indent = 2;
            list.TextIndent = 4;
            list.Brush = brush;
            list.Marker = marker;

            //Draw list on a page at the specified location
            list.Draw(page, x, y);

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

Imports System
Imports Spire.Pdf
Imports Spire.Pdf.Graphics
Imports Spire.Pdf.Lists

Namespace CustomizeBulletPointsWithImage
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument()

            'Set the margin
            Dim margin As PdfMargins =  New PdfMargins(30)

            'Add a page
            Dim page As PdfPageBase =  doc.Pages.Add(PdfPageSize.A4,margin)

            'Create fonts
            Dim titleFont As PdfFont =  New PdfFont(PdfFontFamily.TimesRoman,12f,PdfFontStyle.Bold)
            Dim listFont As PdfFont =  New PdfFont(PdfFontFamily.TimesRoman,12f,PdfFontStyle.Regular)

            'Create a brush
            Dim brush As PdfBrush =  PdfBrushes.Black

            'Specify the initial coordinate
            Dim x As single =  10
            Dim y As single =  20

            'Draw title
            Dim title As String =  "Project Task To-Do List:"
            page.Canvas.DrawString(title, titleFont, brush, x, y)
            y = y + CType(titleFont.MeasureString(title).Height, single)
            y = y + 5

            'Specify the marker style to image
            Dim marker As PdfMarker =  New PdfMarker(PdfUnorderedMarkerStyle.CustomImage)

            'Set the image for the marker
            marker.Image = PdfImage.FromFile("C:\Users\Administrator\Desktop\checkmark.jpg")

            'Create an unordered list
            String listContent = "Define projects and tasks you're working on\n"
                    + "Assign people to tasks\n"
                    + "Define the priority levels of your tasks\n"
                    + "Keep track of the progress status of your tasks\n"
                    Dim "Mark tasks as done when completed" As +
            Dim list As PdfList =  New PdfList(listContent)

            'Set the font, indent, text indent, brush, maker of the list
            list.Font = listFont
            list.Indent = 2
            list.TextIndent = 4
            list.Brush = brush
            list.Marker = marker

            'Draw list on a page at the specified location
            list.Draw(page, x, y)

            'Save to file
            doc.SaveToFile("ImageBullets.pdf")
        End Sub
    End Class
End Namespace

using System;
using Spire.Pdf;
using Spire.Pdf.Graphics;
using Spire.Pdf.Lists;

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

            //Set the margin
            PdfMargins margin = new PdfMargins(30);

            //Add a page
            PdfPageBase page = doc.Pages.Add(PdfPageSize.A4, margin);

            //Specify the initial coordinate
            float x = 10;
            float y = 20;

            //Create two brushes
            PdfBrush blackBrush = PdfBrushes.Black;
            PdfBrush purpleBrush = PdfBrushes.Purple;

            //Create two fonts
            PdfFont titleFont = new PdfFont(PdfFontFamily.TimesRoman, 12f, PdfFontStyle.Bold);
            PdfFont listFont = new PdfFont(PdfFontFamily.TimesRoman, 12f, PdfFontStyle.Regular);

            //Create a maker for ordered list
            PdfOrderedMarker marker = new PdfOrderedMarker(PdfNumberStyle.Numeric, listFont);

            //Draw title
            String title = "Below is a Nested Numbered List:";
            page.Canvas.DrawString(title, titleFont, blackBrush, x, y);
            y = y + (float)titleFont.MeasureString(title).Height;
            y = y + 5;

            //Create a parent list
            String parentListContent = "Parent Item 1\n"
                    + "Parent Item 2";
            PdfSortedList parentList = new PdfSortedList(parentListContent);
            parentList.Font = listFont;
            parentList.Indent = 2;
            parentList.Brush = purpleBrush;
            parentList.Marker = marker;

            //Create a sub list - "subList_1"
            String subListContent_1 = "Sub Item 1\n"
                    + "Sub Item 2\n"
                    + "Sub Item 3\n"
                    + "Sub Item 4";
            PdfSortedList subList_1 = new PdfSortedList(subListContent_1);
            subList_1.Indent = 12;
            subList_1.Font = listFont;
            subList_1.Brush = blackBrush;
            subList_1.Marker = marker;
            subList_1.MarkerHierarchy = true;

            //Create another sub list -"subList_2"
            String subListContent_2 = "Sub Item 1\n"
                    + "Sub Item 2\n"
                    + "Sub Item 3";
            PdfSortedList subList_2 = new PdfSortedList(subListContent_2);
            subList_2.Indent = 12;
            subList_2.Font = listFont;
            subList_2.Brush = blackBrush;
            subList_2.Marker = marker;
            subList_2.MarkerHierarchy = true;

            //Create a sub-sub list - "subList_1"
            String subSubListContent_1 = "Sub Sub Item 1\n"
                    + "Sub Sub Item 2";
            PdfSortedList subSubList = new PdfSortedList(subSubListContent_1);
            subSubList.Indent = 20;
            subSubList.Font = listFont;
            subSubList.Brush = blackBrush;
            subSubList.Marker = marker;
            subSubList.MarkerHierarchy = true;

            //Set subList_1 as sub list of the first item of parent list
            PdfListItem item_1 = parentList.Items[0];
            item_1.SubList = subList_1;

            //Set subList_2 as sub list of the second item of parent list
            PdfListItem item_2 = parentList.Items[1];
            item_2.SubList = subList_2;

            //Set subSubList as sub list of the first item of subList_1
            PdfListItem item_1_1 = subList_1.Items[0];
            item_1_1.SubList = subSubList;

            //Draw parent list
            parentList.Draw(page, x, y);

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

Imports System
Imports Spire.Pdf
Imports Spire.Pdf.Graphics
Imports Spire.Pdf.Lists

Namespace CreateMultiLevelLists
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument()

            'Set the margin
            Dim margin As PdfMargins =  New PdfMargins(30)

            'Add a page
            Dim page As PdfPageBase =  doc.Pages.Add(PdfPageSize.A4,margin)

            'Specify the initial coordinate
            Dim x As single =  10
            Dim y As single =  20

            'Create two brushes
            Dim blackBrush As PdfBrush =  PdfBrushes.Black
            Dim purpleBrush As PdfBrush =  PdfBrushes.Purple

            'Create two fonts
            Dim titleFont As PdfFont =  New PdfFont(PdfFontFamily.TimesRoman,12f,PdfFontStyle.Bold)
            Dim listFont As PdfFont =  New PdfFont(PdfFontFamily.TimesRoman,12f,PdfFontStyle.Regular)

            'Create a maker for ordered list
            Dim marker As PdfOrderedMarker =  New PdfOrderedMarker(PdfNumberStyle.Numeric,listFont)

            'Draw title
            Dim title As String =  "Below is a Nested Numbered List:"
            page.Canvas.DrawString(title, titleFont, blackBrush, x, y)
            y = y + CType(titleFont.MeasureString(title).Height, single)
            y = y + 5

            'Create a parent list
            String parentListContent = "Parent Item 1\n"
                    Dim "Parent Item 2" As +
            Dim parentList As PdfSortedList =  New PdfSortedList(parentListContent)
            parentList.Font = listFont
            parentList.Indent = 2
            parentList.Brush = purpleBrush
            parentList.Marker = marker

            'Create a sub list - "subList_1"
            String subListContent_1 = "Sub Item 1\n"
                    + "Sub Item 2\n"
                    + "Sub Item 3\n"
                    Dim "Sub Item 4" As +
            Dim subList_1 As PdfSortedList =  New PdfSortedList(subListContent_1)
            subList_1.Indent = 12
            subList_1.Font = listFont
            subList_1.Brush = blackBrush
            subList_1.Marker = marker
            subList_1.MarkerHierarchy = True

            'Create another sub list -"subList_2"
            String subListContent_2 = "Sub Item 1\n"
                    + "Sub Item 2\n"
                    Dim "Sub Item 3" As +
            Dim subList_2 As PdfSortedList =  New PdfSortedList(subListContent_2)
            subList_2.Indent = 12
            subList_2.Font = listFont
            subList_2.Brush = blackBrush
            subList_2.Marker = marker
            subList_2.MarkerHierarchy = True

            'Create a sub-sub list - "subList_1"
            String subSubListContent_1 = "Sub Sub Item 1\n"
                    Dim "Sub Sub Item 2" As +
            Dim subSubList As PdfSortedList =  New PdfSortedList(subSubListContent_1)
            subSubList.Indent = 20
            subSubList.Font = listFont
            subSubList.Brush = blackBrush
            subSubList.Marker = marker
            subSubList.MarkerHierarchy = True

            'Set subList_1 as sub list of the first item of parent list
            Dim item_1 As PdfListItem =  parentList.Items(0)
            item_1.SubList = subList_1

            'Set subList_2 as sub list of the second item of parent list
            Dim item_2 As PdfListItem =  parentList.Items(1)
            item_2.SubList = subList_2

            'Set subSubList as sub list of the first item of subList_1
            Dim item_1_1 As PdfListItem =  subList_1.Items(0)
            item_1_1.SubList = subSubList

            'Draw parent list
            parentList.Draw(page, x, y)

            'Save to file
            doc.SaveToFile("MultiLevelList.pdf")
        End Sub
    End Class
End Namespace

PM> Install-Package Spire.XLS

using Spire.Xls;

namespace LockCells
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a Workbook instance
            Workbook workbook = new Workbook();
            //Load an Excel file
            workbook.LoadFromFile("Input.xlsx");

            //Get the first worksheet
            Worksheet sheet = workbook.Worksheets[0];

            //Unlock all cells in the used range of the worksheet
            CellRange usedRange = sheet.Range;            
            usedRange.Style.Locked = false;

            //Lock specific cells
            CellRange cells = sheet.Range["A1:C3"]; 
            cells.Style.Locked = true;

            //Protect the worksheet with password
            sheet.Protect("123456", SheetProtectionType.All);

            //Save the result file
            workbook.SaveToFile("LockCells.xlsx", ExcelVersion.Version2016);
        }
    }
}

Imports Spire.Xls

Namespace LockCells
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Create a Workbook instance
            Dim workbook As Workbook = New Workbook()
            'Load an Excel file
            workbook.LoadFromFile("Input.xlsx")

            'Get the first worksheet
            Dim sheet As Worksheet = workbook.Worksheets(0)

            'Unlock all cells in the used range of the worksheet
            Dim usedRange As CellRange = sheet.Range
            usedRange.Style.Locked = False

            'Lock specific cells
            Dim cells As CellRange = sheet.Range("A1:C3")
            cells.Style.Locked = True

            'Protect the worksheet with password
            sheet.Protect("123456", SheetProtectionType.All)

            'Save the result file
            workbook.SaveToFile("LockCells.xlsx", ExcelVersion.Version2016)
        End Sub
    End Class
End Namespace