PM> Install-Package Spire.Presentation

using Spire.Presentation;
using Spire.Presentation.Drawing;
using System.Drawing;

namespace CreateNumberedList
{
    internal class Program
    {
        static void Main(string[] args)
        {
            //Create a Presentation object
            Presentation presentation = new Presentation();
            //Get the first slide
            ISlide slide = presentation.Slides[0];

            //Add a shape to the slide and set the shape style
            IAutoShape shape = slide.Shapes.AppendShape(ShapeType.Rectangle, new RectangleF(50, 50, 300, 200));
            shape.Fill.FillType = FillFormatType.None;
            shape.Line.FillType= FillFormatType.None;

            //Add text to the default paragraph
            TextParagraph paragraph = shape.TextFrame.Paragraphs[0];
            paragraph.Text = "Required Web Development Skills:";
            paragraph.Alignment = TextAlignmentType.Left;
            paragraph.TextRanges[0].Fill.FillType = FillFormatType.Solid;
            paragraph.TextRanges[0].Fill.SolidColor.Color = Color.Black;

            //Specify the list items
            string[] listItems = new string[] {
                " Command-line Unix",
                " Vim",
                " HTML",
                " CSS",
                " Python",
                " JavaScript",
                " SQL"
            };

            //Create a numbered list
            foreach (string item in listItems)
            {
                TextParagraph textParagraph = new TextParagraph();
                textParagraph.Text = item;
                textParagraph.Alignment = TextAlignmentType.Left;
                textParagraph.TextRanges[0].Fill.FillType = FillFormatType.Solid;
                textParagraph.TextRanges[0].Fill.SolidColor.Color = Color.Black;

                textParagraph.BulletType = TextBulletType.Numbered;
                textParagraph.BulletStyle = NumberedBulletStyle.BulletArabicPeriod;
                shape.TextFrame.Paragraphs.Append(textParagraph);
            }

            //Save the result document
            presentation.SaveToFile("NumberedList.pptx", FileFormat.Pptx2013);
        }
    }
}

Imports Spire.Presentation
Imports Spire.Presentation.Drawing
Imports System.Drawing

Namespace CreateNumberedList
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Create a Presentation object
            Dim presentation As Presentation = New Presentation()
            'Get the first slide
            Dim slide As ISlide = presentation.Slides(0)

            'Add a shape to the slide and set the shape style
            Dim shape As IAutoShape = slide.Shapes.AppendShape(ShapeType.Rectangle, New RectangleF(50, 50, 300, 200))
            shape.Fill.FillType = FillFormatType.None
            shape.Line.FillType = FillFormatType.None

            'Add text to the default paragraph
            Dim paragraph As TextParagraph = shape.TextFrame.Paragraphs(0)
            paragraph.Text = "Required Web Development Skills:"
            paragraph.Alignment = TextAlignmentType.Left
            paragraph.TextRanges(0).Fill.FillType = FillFormatType.Solid
            paragraph.TextRanges(0).Fill.SolidColor.Color = Color.Black

            'Specify the list items
            Dim listItems = New String() {" Command-line Unix", " Vim", " HTML", " CSS", " Python", " JavaScript", " SQL"}

            'Create a numbered list
            For Each item In listItems
                Dim textParagraph As TextParagraph = New TextParagraph()
                textParagraph.Text = item
                textParagraph.Alignment = TextAlignmentType.Left
                textParagraph.TextRanges(0).Fill.FillType = FillFormatType.Solid
                textParagraph.TextRanges(0).Fill.SolidColor.Color = Color.Black

                textParagraph.BulletType = TextBulletType.Numbered
                textParagraph.BulletStyle = NumberedBulletStyle.BulletArabicPeriod
                shape.TextFrame.Paragraphs.Append(textParagraph)
            Next

            'Save the result document
            presentation.SaveToFile("NumberedList.pptx", FileFormat.Pptx2013)
        End Sub
    End Class
End Namespace

using Spire.Presentation;
using Spire.Presentation.Drawing;
using System.Drawing;

namespace CreateSymbolBulletedList
{
    internal class Program
    {
        static void Main(string[] args)
        {
            //Create a Presentation object
            Presentation presentation = new Presentation();
            //Get the first slide
            ISlide slide = presentation.Slides[0];

            //Add a shape to the slide and set the shape style
            IAutoShape shape = slide.Shapes.AppendShape(ShapeType.Rectangle, new RectangleF(50, 50, 350, 200));
            shape.Fill.FillType = FillFormatType.None;
            shape.Line.FillType = FillFormatType.None;

            //Add text to the default paragraph
            TextParagraph paragraph = shape.TextFrame.Paragraphs[0];
            paragraph.Text = "Computer Science Subjects:";
            paragraph.Alignment = TextAlignmentType.Left;
            paragraph.TextRanges[0].Fill.FillType = FillFormatType.Solid;
            paragraph.TextRanges[0].Fill.SolidColor.Color = Color.Black;

            //Specify the list items
            string[] listItems = new string[] {
                " Data Structure",
                " Algorithm",
                " Computer Networks",
                " Operating System",
                " Theory of Computations",
                " C Programming",
                " Computer Organization and Architecture"
            };

            //Create a symbol bulleted list
            foreach (string item in listItems)
            {
                TextParagraph textParagraph = new TextParagraph();
                textParagraph.Text = item;
                textParagraph.Alignment = TextAlignmentType.Left;
                textParagraph.TextRanges[0].Fill.FillType = FillFormatType.Solid;
                textParagraph.TextRanges[0].Fill.SolidColor.Color = Color.Black;
                textParagraph.BulletType = TextBulletType.Symbol;
                shape.TextFrame.Paragraphs.Append(textParagraph);
            }

            //Save the result document
            presentation.SaveToFile("SymbolBulletedList.pptx", FileFormat.Pptx2013);
        }
    }
}

Imports Spire.Presentation
Imports Spire.Presentation.Drawing
Imports System.Drawing

Namespace CreateSymbolBulletedList
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Create a Presentation object
            Dim presentation As Presentation = New Presentation()
            'Get the first slide
            Dim slide As ISlide = presentation.Slides(0)

            'Add a shape to the slide and set the shape style
            Dim shape As IAutoShape = slide.Shapes.AppendShape(ShapeType.Rectangle, New RectangleF(50, 50, 350, 200))
            shape.Fill.FillType = FillFormatType.None
            shape.Line.FillType = FillFormatType.None

            'Add text to the default paragraph
            Dim paragraph As TextParagraph = shape.TextFrame.Paragraphs(0)
            paragraph.Text = "Computer Science Subjects:"
            paragraph.Alignment = TextAlignmentType.Left
            paragraph.TextRanges(0).Fill.FillType = FillFormatType.Solid
            paragraph.TextRanges(0).Fill.SolidColor.Color = Color.Black

            'Specify the list items
            Dim listItems = New String() {" Data Structure", " Algorithm", " Computer Networks", " Operating System", " Theory of Computations", " C Programming", " Computer Organization and Architecture"}

            'Create a symbol bulleted list
            For Each item In listItems
                Dim textParagraph As TextParagraph = New TextParagraph()
                textParagraph.Text = item
                textParagraph.Alignment = TextAlignmentType.Left
                textParagraph.TextRanges(0).Fill.FillType = FillFormatType.Solid
                textParagraph.TextRanges(0).Fill.SolidColor.Color = Color.Black
                textParagraph.BulletType = TextBulletType.Symbol
                shape.TextFrame.Paragraphs.Append(textParagraph)
            Next

            'Save the result document
            presentation.SaveToFile("SymbolBulletedList.pptx", FileFormat.Pptx2013)
        End Sub
    End Class
End Namespace

using Spire.Presentation;
using Spire.Presentation.Drawing;
using System.Drawing;

namespace CreateImageBulletedList
{
    internal class Program
    {
        static void Main(string[] args)
        {
            //Create a Presentation object
            Presentation presentation = new Presentation();
            //Get the first slide
            ISlide slide = presentation.Slides[0];

            //Add a shape to the slide and set the shape style
            IAutoShape shape = slide.Shapes.AppendShape(ShapeType.Rectangle, new RectangleF(50, 50, 400, 180));
            shape.Fill.FillType = FillFormatType.None;
            shape.Line.FillType = FillFormatType.None;

            //Add text to the default paragraph
            TextParagraph paragraph = shape.TextFrame.Paragraphs[0];
            paragraph.Text = "Project Task To-Do List:";
            paragraph.Alignment = TextAlignmentType.Left;
            paragraph.TextRanges[0].Fill.FillType = FillFormatType.Solid;
            paragraph.TextRanges[0].Fill.SolidColor.Color = Color.Black;

            //Specify the list items
            string[] listItems = new string[] {
                " Define projects and tasks you're working on",
                " Assign people to tasks",
                " Define the priority levels of your tasks",
                " Keep track of the progress status of your tasks",
                " Mark tasks as done when completed"
            };

            //Create an image bulleted list
            foreach (string item in listItems)
            {
                TextParagraph textParagraph = new TextParagraph();
                textParagraph.Text = item;
                textParagraph.Alignment = TextAlignmentType.Left;
                textParagraph.TextRanges[0].Fill.FillType = FillFormatType.Solid;
                textParagraph.TextRanges[0].Fill.SolidColor.Color = Color.Black;
                textParagraph.BulletType = TextBulletType.Picture;
                IImageData image = presentation.Images.Append(Image.FromFile("icon.png"));
                textParagraph.BulletPicture.EmbedImage = image;
                shape.TextFrame.Paragraphs.Append(textParagraph);
            }

            //Save the result document
            presentation.SaveToFile("ImageBulletedList.pptx", FileFormat.Pptx2013);
        }
    }
}

Imports Spire.Presentation
Imports Spire.Presentation.Drawing
Imports System.Drawing

Namespace CreateImageBulletedList
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Create a Presentation object
            Dim presentation As Presentation = New Presentation()
            'Get the first slide
            Dim slide As ISlide = presentation.Slides(0)

            'Add a shape to the slide and set the shape style
            Dim shape As IAutoShape = slide.Shapes.AppendShape(ShapeType.Rectangle, New RectangleF(50, 50, 400, 180))
            shape.Fill.FillType = FillFormatType.None
            shape.Line.FillType = FillFormatType.None

            'Add text to the default paragraph
            Dim paragraph As TextParagraph = shape.TextFrame.Paragraphs(0)
            paragraph.Text = "Project Task To-Do List:"
            paragraph.Alignment = TextAlignmentType.Left
            paragraph.TextRanges(0).Fill.FillType = FillFormatType.Solid
            paragraph.TextRanges(0).Fill.SolidColor.Color = Color.Black

            'Specify the list items
            Dim listItems = New String() {" Define projects and tasks you're working on", " Assign people to tasks", " Define the priority levels of your tasks", " Keep track of the progress status of your tasks", " Mark tasks as done when completed"}

            'Create an image bulleted list
            For Each item In listItems
                Dim textParagraph As TextParagraph = New TextParagraph()
                textParagraph.Text = item
                textParagraph.Alignment = TextAlignmentType.Left
                textParagraph.TextRanges(0).Fill.FillType = FillFormatType.Solid
                textParagraph.TextRanges(0).Fill.SolidColor.Color = Color.Black
                textParagraph.BulletType = TextBulletType.Picture
                Dim image As IImageData = presentation.Images.Append(Image.FromFile("icon.png"))
                textParagraph.BulletPicture.EmbedImage = image
                shape.TextFrame.Paragraphs.Append(textParagraph)
            Next

            'Save the result document
            presentation.SaveToFile("ImageBulletedList.pptx", FileFormat.Pptx2013)
        End Sub
    End Class
End Namespace

PM> Install-Package Spire.Presentation

using Spire.Presentation;

namespace ConvertPowerPointToPdf
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a Presentation object
            Presentation presentation = new Presentation();

            // Load a PowerPoint file
            presentation.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Input.pptx");

            // Save it to PDF
            presentation.SaveToFile("ToPdf.pdf", FileFormat.PDF);

            // Dispose resources
            presentation.Dispose();
        }
    }
}

using Spire.Presentation;
using Spire.Presentation.External.Pdf;

namespace ConvertPowerPointToPdfa
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a Presentation object
            Presentation presentation = new Presentation();

            // Load a PowerPoint file
            presentation.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Input.pptx");

            // Get the SaveToPdfOption object
            SaveToPdfOption options = presentation.SaveToPdfOption;

            // Set the pdf conformance level to pdf_a1a
            options.PdfConformanceLevel = PdfConformanceLevel.Pdf_A1A;

            // Save the presentation to PDF
            presentation.SaveToFile("ToPdfa.pdf",FileFormat.PDF);

            // Dispose resources
            presentation.Dispose();
        }
    }
}

using Spire.Presentation;
using Spire.Presentation.External.Pdf;

namespace ConvertPowerPointToPasswordProtectedPdf
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a Presentation object
            Presentation presentation = new Presentation();

            // Load a PowerPoint file
            presentation.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Input.pptx");

            // Get the SaveToPdfOption object
            SaveToPdfOption option = presentation.SaveToPdfOption;

            // Encrypt the generated document with a password
            option.PdfSecurity.Encrypt("abc-123",PdfPermissionsFlags.Print | PdfPermissionsFlags.FillFields);

            // Save the presentation to PDF
            presentation.SaveToFile("ToEncryptedPdf.pdf", FileFormat.PDF);

            // Dispose resources
            presentation.Dispose();
        }
    }
}

using Spire.Presentation;

namespace ConvertPowerPointToPdfWithHiddenSlides
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a Presentation object
            Presentation presentation = new Presentation();

            // Load a PowerPoint file
            presentation.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Input.pptx");

            // Get the SaveToPdfOption object
            SaveToPdfOption option = presentation.SaveToPdfOption;

            // Enable ContainHiddenSlides option
            option.ContainHiddenSlides = true;

            // Save the presentation to PDF
            presentation.SaveToFile("ToPdfWithHiddenSlides.pdf", FileFormat.PDF);

            // Dispose resources
            presentation.Dispose();
        }
    }
}

using Spire.Presentation;
using System.Drawing;

namespace ConvertPowerPointToPdfWithCustomSlideSize
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a Presentation object
            Presentation presentation = new Presentation();

            // Load a PowerPoint file
            presentation.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Input.pptx");

            // Set the slide size type as custom
            presentation.SlideSize.Type = SlideSizeType.Custom;

            // Set the custom slide size
            presentation.SlideSize.Size = new SizeF(750, 500);

            // Or, you can set the slide size to a standard slide size like A4
            // presentation.SlideSize.Type = SlideSizeType.A4;

            // Fit content to the new size of slide
            presentation.SlideSizeAutoFit = true;

            // Save the presentation to PDF
            presentation.SaveToFile("ToPdfWithCustomSlideSize.pdf", FileFormat.PDF);

            // Dispose resources
            presentation.Dispose();
        }
    }
}

using Spire.Presentation;

namespace ConvertSpecificSlideToPdf
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a Presentation object
            Presentation presentation = new Presentation();

            // Load a PowerPoint file
            presentation.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Input.pptx");

            // Get a specific slide
            ISlide slide = presentation.Slides[1];

            // Save it to PDF
            slide.SaveToFile("SlideToPdf.pdf", FileFormat.PDF);

            // Dispose resources
            presentation.Dispose();
        }
    }
}