PM> Install-Package Spire.PDF

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

namespace DuplicatePage
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a PdfDocument instance
            PdfDocument pdf = new PdfDocument();

            //Load a PDF file
            pdf.LoadFromFile("Butterflies.pdf");

            //Get the first page
            PdfPageBase page = pdf.Pages[0];

            //Get the size of the page
            SizeF size = page.Size;

            //Create a template based on the page
            PdfTemplate template = page.CreateTemplate();

            //Add a new page the same size as the first page
            page = pdf.Pages.Add(size, new PdfMargins(0));
            //Insert a new page at the specified location
            //page = pdf.Pages.Insert(1, size, new PdfMargins(0));

            //Draw the template on the newly added page
            page.Canvas.DrawTemplate(template, new PointF(0, 0));

            //Save the PDF file
            pdf.SaveToFile("CopyPDFPages.pdf");
        }
    }
}

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

namespace CopyPageToAnother
{
    class Program
    {
        static void Main(string[] args)
        {
            //Load the first PDF file
            PdfDocument pdf1 = new PdfDocument();
            pdf1.LoadFromFile("Butterflies.pdf");

            //Load the second PDF file
            PdfDocument pdf2 = new PdfDocument();
            pdf2.LoadFromFile("SamplePDF.pdf");

            //Get the first page in the first PDF file
            PdfPageBase page = pdf1.Pages[0];

            //Get the size of the page
            SizeF size = page.Size;

            //Create a template based on the page
            PdfTemplate template = page.CreateTemplate();

            //Insert a new page at a specified location in the second PDF file
            PdfPageBase newPage = pdf2.Pages.Insert(0, size, new PdfMargins(0));

            //Add a new page at the end of the second PDF file
            //PdfPageBase newPage = pdf2.Pages.Add(size, new PdfMargins(0));

            //Draw the template on the newly added page
            newPage.Canvas.DrawTemplate(template, new PointF(0, 0));

            //Save the result file
            pdf2.SaveToFile("CopyPagesToAnotherPDF.pdf");
        }
    }
}

PM> Install-Package Spire.PDF

using System.Drawing;
using Spire.Pdf;

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

            //Load a PDF file from disk
            pdf.LoadFromFile("Sample1.pdf");

            //Get the first page
            PdfPageBase page = pdf.Pages[0];

            //Crop the page by the specified area
            page.CropBox = new RectangleF(0, 300, 600, 260);

            //Save the result file
            pdf.SaveToFile("CropPDF.pdf");
            pdf.Close();
        }
    }
}

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

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

            //Load a PDF file from disk
            pdf.LoadFromFile("Sample1.pdf");

            //Get the first page
            PdfPageBase page = pdf.Pages[0];

            //Crop the page by the specified area
            page.CropBox = new RectangleF(0, 300, 600, 260);

            //Convert the page to an image
            Image image = pdf.SaveAsImage(0, PdfImageType.Bitmap);

            //Save the image as a PNG file
            image.Save("CropPDFSaveAsImage.png", ImageFormat.Png);

            //Save the image as a JPG file
            //image.Save("ToJPG.jpg", ImageFormat.Jpeg);

            //Save the image as a BMP file
            //image.Save("ToBMP.bmp", ImageFormat.Bmp);
        }
    }
}

PM> Install-Package Spire.PDF 

using System.Text;
using Spire.Pdf;
using Spire.Pdf.Graphics;

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

            //Load a PDF file from disk
            pdf.LoadFromFile("SamplePDF.pdf");

            //Get the first page 
            PdfPageBase page = pdf.Pages[0];

            //Get the width and height of the page in "point"
            float pointWidth = page.Size.Width;
            float pointHeight = page.Size.Height;

            //Create PdfUnitConvertor to convert the unit
            PdfUnitConvertor unitCvtr = new PdfUnitConvertor();

            //Convert size units from points to pixels
            float pixelWidth = unitCvtr.ConvertUnits(pointWidth, PdfGraphicsUnit.Point, PdfGraphicsUnit.Pixel);
            float pixelHeight = unitCvtr.ConvertUnits(pointHeight, PdfGraphicsUnit.Point, PdfGraphicsUnit.Pixel);

            //Convert size units from points to inches
            float inchWidth = unitCvtr.ConvertUnits(pointWidth, PdfGraphicsUnit.Point, PdfGraphicsUnit.Inch);
            float inchHeight = unitCvtr.ConvertUnits(pointHeight, PdfGraphicsUnit.Point, PdfGraphicsUnit.Inch);

            //Convert size units from points to centimeters
            float centimeterWidth = unitCvtr.ConvertUnits(pointWidth, PdfGraphicsUnit.Point, PdfGraphicsUnit.Centimeter);
            float centimeterHeight = unitCvtr.ConvertUnits(pointHeight, PdfGraphicsUnit.Point, PdfGraphicsUnit.Centimeter);

            //Create a StringBuilder instance 
            StringBuilder content = new StringBuilder();

            //Add the page size information to the StringBuilder instance 
            content.AppendLine("The page size of the file in points is (width: " + pointWidth + "pt, height: " + pointHeight + "pt).");
            content.AppendLine("The page size of the file in pixels is (width: " + pixelWidth + "pixel, height: " + pixelHeight + "pixel).");
            content.AppendLine("The page size of the file in inches is (width: " + inchWidth + "inch, height: " + inchHeight + "inch).");
            content.AppendLine("The page size of the file in centimeters is (width: " + centimeterWidth + "cm, height: " + centimeterHeight + "cm).");

            //Save to a txt file
            File.WriteAllText("GetPageSize.txt", content.ToString());
        }
    }
}

using Spire.Pdf;

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

            //Load a PDF file from disk
            pdf.LoadFromFile("SamplePDF.pdf");

            //Get the first page 
            PdfPageBase page = pdf.Pages[0];

            //Get the width and height of the page
            float width = page.Size.Width;
            float height = page.Size.Height;

            //Compare the values of page width and height 
            if (width > height)
            {
                Console.WriteLine("The page orientation is Landscape.");
            }

            else
            {
                Console.WriteLine("The page orientation is Portrait.");
            }
        }
    }
}

using Spire.Pdf;

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

            //Load a PDF file from disk
            pdf.LoadFromFile("E:\\PythonPDF\\Sample.pdf");

            //Get the first page 
            PdfPageBase page = pdf.Pages[0];

            //Get the rotation angle of the current page
            PdfPageRotateAngle rotationAngle = page.Rotation;
            string rotation = rotationAngle.ToString();

            //Output the page rotation angle information
            Console.WriteLine("The rotation angle of the current page is: " + rotation);
        }
    }
}

PM> Install-Package Spire.PDF

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

namespace IncreaseMargins
{
    class Program
    {
        static void Main(string[] args)
        {
            //Load the original PDF document
            PdfDocument originalPdf = new PdfDocument("C:\\Users\\Administrator\\Desktop\\sample.pdf");

            //Get the first page
            PdfPageBase firstPage = originalPdf.Pages[0];

            //Create a new PdfDocument object
            PdfDocument newPdf = new PdfDocument();

            //Set increasing value of the margins
            PdfMargins margins = newPdf.PageSettings.Margins;
            margins.Top = 40;
            margins.Bottom=40;
            margins.Left=40;
            margins.Right= 40;

            //Calculate the new page size
            SizeF sizeF = new SizeF(firstPage.Size.Width + margins.Left + margins.Right, firstPage.Size.Height + margins.Top + margins.Bottom);

            //Loop through the pages in the original document
            for (int i = 0; i < originalPdf.Pages.Count; i++)
            {
                //Create a template based on a spcific page
                PdfTemplate pdfTemplate = originalPdf.Pages[i].CreateTemplate();

                //Add a page to the new PDF
                PdfPageBase page = newPdf.Pages.Add(sizeF);

                //Draw template on the page
                pdfTemplate.Draw(page, 0, 0);
            }

            //Save the new document
            newPdf.SaveToFile("IncreaseMargins.pdf", FileFormat.PDF);
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Graphics
Imports System.Drawing
 
Namespace IncreaseMargins
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Load the original PDF document
            Dim originalPdf As PdfDocument =  New PdfDocument("C:\\Users\\Administrator\\Desktop\\sample.pdf") 
 
            'Get the first page
            Dim firstPage As PdfPageBase =  originalPdf.Pages(0) 
 
            'Create a new PdfDocument object
            Dim NewPdf As PdfDocument =  New PdfDocument() 
 
            'Set increasing value of the margins
            Dim margins As PdfMargins =  NewPdf.PageSettings.Margins 
            margins.Top = 40
            margins.Bottom=40
            margins.Left=40
            margins.Right= 40
 
            'Calculate the new page size
            Dim sizeF As SizeF =  New SizeF(firstPage.Size.Width + margins.Left + margins.Right,firstPage.Size.Height + margins.Top + margins.Bottom) 
 
            'Loop through the pages in the original document
            Dim i As Integer
            For  i = 0 To  originalPdf.Pages.Count- 1  Step  i + 1
                'Create a template based on a spcific page
                Dim pdfTemplate As PdfTemplate =  originalPdf.Pages(i).CreateTemplate() 
 
                'Add a page to the new PDF
                Dim page As PdfPageBase =  NewPdf.Pages.Add(sizeF) 
 
                'Draw template on the page
                pdfTemplate.Draw(page, 0, 0)
            Next
 
            'Save the new document
            NewPdf.SaveToFile("IncreaseMargins.pdf", FileFormat.PDF)
        End Sub
    End Class
End Namespace

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

namespace DecreaseMargins
{
    class Program
    {
        static void Main(string[] args)
        {
            //Load the original PDF document
            PdfDocument originalPdf = new PdfDocument("C:\\Users\\Administrator\\Desktop\\sample.pdf");

            //Get the first page
            PdfPageBase firstPage = originalPdf.Pages[0]; 

            //Create a new PdfDocument object
            PdfDocument newPdf = new PdfDocument();

            //Set decreasing value
            float left = -20;
            float right = -20;
            float top = -20;
            float bottom = -20;

            //Calculate the new page size
            SizeF sizeF = new SizeF(firstPage.Size.Width + left + right, firstPage.Size.Height + top + bottom);

            //Loop through the pages in the original document
            for (int i = 0; i < originalPdf.Pages.Count; i++)
            {
                //Create a template based on a specific page
                PdfTemplate pdfTemplate = originalPdf.Pages[i].CreateTemplate();

                //Add a page to the new PDF
                PdfPageBase page = newPdf.Pages.Add(sizeF, new PdfMargins(0));

                //Draw template on the page
                pdfTemplate.Draw(page, left, top);
            }

            //Save the new document
            newPdf.SaveToFile("DecreaseMargins.pdf", FileFormat.PDF);
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Graphics
Imports System.Drawing
 
Namespace DecreaseMargins
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Load the original PDF document
            Dim originalPdf As PdfDocument =  New PdfDocument("C:\\Users\\Administrator\\Desktop\\sample.pdf") 
 
            'Get the first page
            Dim firstPage As PdfPageBase =  originalPdf.Pages(0) 
 
            'Create a new PdfDocument object
            Dim NewPdf As PdfDocument =  New PdfDocument() 
 
            'Set decreasing value
            Dim left As single =  -20 
            Dim right As single =  -20 
            Dim top As single =  -20 
            Dim bottom As single =  -20 
 
            'Calculate the new page size
            Dim sizeF As SizeF =  New SizeF(firstPage.Size.Width + left + right,firstPage.Size.Height + top + bottom) 
 
            'Loop through the pages in the original document
            Dim i As Integer
            For  i = 0 To  originalPdf.Pages.Count- 1  Step  i + 1
                'Create a template based on a specific page
                Dim pdfTemplate As PdfTemplate =  originalPdf.Pages(i).CreateTemplate() 
 
                'Add a page to the new PDF
                Dim page As PdfPageBase =  NewPdf.Pages.Add(sizeF,New PdfMargins(0)) 
 
                'Draw template on the page
                pdfTemplate.Draw(page, left, top)
            Next
 
            'Save the new document
            NewPdf.SaveToFile("DecreaseMargins.pdf", FileFormat.PDF)
        End Sub
    End Class
End Namespace

PM> Install-Package Spire.PDF

using Spire.Pdf;

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

            //Load a sample PDF document
            pdf.LoadFromFile("input.pdf");

            //Rearrange pages by page index
            pdf.Pages.ReArrange(new int[] { 1, 0, 2, 3 });

            //Save the document
            pdf.SaveToFile("ChangeOrder.pdf");
            pdf.Close();
        }
    }
}

Imports Spire.Pdf

Namespace RearrangePDF
    Class Program
        Private Shared Sub Main(ByVal args As String())

            'Create a PdfDocument object
            Dim pdf As PdfDocument = New PdfDocument()

            'Load a sample PDF document
            pdf.LoadFromFile("input.pdf")

            'Rearrange pages by page index
            pdf.Pages.ReArrange(New Integer() {1, 0, 2, 3})

            'Save the document
            pdf.SaveToFile("ChangeOrder.pdf")
            pdf.Close()
        End Sub
    End Class
End Namespace

PM> Install-Package Spire.PDF

using Spire.Pdf.AutomaticFields;
using Spire.Pdf.Graphics;
using Spire.Pdf;
using System.Drawing;
using Spire.Pdf.License;

namespace AddPageNumbersToLeftCorner
{
    class Program
    {
        static void Main(string[] args)
        {
            // Apply your license key
            LicenseProvider.SetLicenseKey("License Key");

            // Create a PdfDocument object
            PdfDocument doc = new PdfDocument();

            // Load a PDF file
            doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Terms of service.pdf");

            // Create font, brush and pen, which determine the appearance of the page numbers to be added
            PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Times New Roman", 12, FontStyle.Regular), true);
            PdfBrush brush = PdfBrushes.Black;
            PdfPen pen = new PdfPen(brush, 1.0f);

            // Create a PdfPageNumberField object and a PdfPageCountField object
            PdfPageNumberField pageNumberField = new PdfPageNumberField();
            PdfPageCountField pageCountField = new PdfPageCountField();

            // Create a PdfCompositeField object to combine page count field and page number field in a single field
            PdfCompositeField compositeField = new PdfCompositeField(font, brush, "Page {0} of {1}", pageNumberField, pageCountField);

            // Get the page size
            SizeF pageSize = doc.Pages[0].Size;

            // Set the location of the composite field
            compositeField.Location = new PointF(72, pageSize.Height - 45);

            // Iterate through the pages in the document
            for (int i = 0; i < doc.Pages.Count; i++)
            {

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

                // Draw a line at the specified position
                page.Canvas.DrawLine(pen, 72, pageSize.Height - 50, pageSize.Width - 72, pageSize.Height - 50);

                // Draw the composite field on the page
                compositeField.Draw(page.Canvas);
            }

            // Save to a different PDF file
            doc.SaveToFile("AddPageNumbersToLeftCorner.pdf");

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

using Spire.Pdf.AutomaticFields;
using Spire.Pdf.Graphics;
using Spire.Pdf;
using System.Drawing;
using Spire.Pdf.License;

namespace AddPageNumbersToCenter
{
    class Program
    {
        static void Main(string[] args)
        {
            // Apply your license key
            LicenseProvider.SetLicenseKey("License Key");

            // Create a PdfDocument object
            PdfDocument doc = new PdfDocument();

            // Load a PDF file
            doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Terms of service.pdf");

            // Create font, brush and pen, which determine the appearance of the page numbers to be added
            PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Times New Roman", 12, FontStyle.Regular), true);
            PdfBrush brush = PdfBrushes.Black;
            PdfPen pen = new PdfPen(brush, 1.0f);

            // Create a PdfPageNumberField object and a PdfPageCountField object
            PdfPageNumberField pageNumberField = new PdfPageNumberField();
            PdfPageCountField pageCountField = new PdfPageCountField();

            // Create a PdfCompositeField object to combine page count field and page number field in a single field
            PdfCompositeField compositeField = new PdfCompositeField(font, brush, "Page {0} of {1}", pageNumberField, pageCountField);


            // Iterate through the pages in the document
            for (int i = 0; i < doc.Pages.Count; i++)
            {

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

                // Get the page size
                SizeF pageSize = doc.Pages[i].Size;

                // Draw a line at the specified position
                page.Canvas.DrawLine(pen, 72, pageSize.Height - 50, pageSize.Width - 72, pageSize.Height - 50);

                // Measure the size the "Page X of Y"
                SizeF pageNumberSize = font.MeasureString(string.Format("Page {0} of {1}", i + 1, doc.Pages.Count));

                // Set the location of the composite field
                compositeField.Location = new PointF((pageSize.Width - pageNumberSize.Width) / 2, pageSize.Height - 45);

                // Draw the composite field on the page
                compositeField.Draw(page.Canvas);

            }

            // Save to a different PDF file
            doc.SaveToFile("AddPageNumbersToCenter.pdf");

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

using Spire.Pdf.AutomaticFields;
using Spire.Pdf.Graphics;
using Spire.Pdf;
using System.Drawing;
using Spire.Pdf.License;

namespace AddPageNumbersToRigthCorner
{
    class Program
    {
        static void Main(string[] args)
        {
            // Apply your license key
            LicenseProvider.SetLicenseKey("License Key");

            // Create a PdfDocument object
            PdfDocument doc = new PdfDocument();

            // Load a PDF file
            doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Terms of service.pdf");

            // Create font, brush and pen, which determine the appearance of the page numbers to be added
            PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Times New Roman", 12, FontStyle.Regular), true);
            PdfBrush brush = PdfBrushes.Black;
            PdfPen pen = new PdfPen(brush, 1.0f);

            // Create a PdfPageNumberField object and a PdfPageCountField object
            PdfPageNumberField pageNumberField = new PdfPageNumberField();
            PdfPageCountField pageCountField = new PdfPageCountField();

            // Create a PdfCompositeField object to combine page count field and page number field in a single field
            PdfCompositeField compositeField = new PdfCompositeField(font, brush, "Page {0} of {1}", pageNumberField, pageCountField);


            // Iterate through the pages in the document
            for (int i = 0; i < doc.Pages.Count; i++)
            {

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

                // Get the page size
                SizeF pageSize = doc.Pages[i].Size;

                // Draw a line at the specified position
                page.Canvas.DrawLine(pen, 72, pageSize.Height - 50, pageSize.Width - 72, pageSize.Height - 50);

                // Measure the size the "Page X of Y"
                SizeF pageNumberSize = font.MeasureString(string.Format("Page {0} of {1}", i + 1, doc.Pages.Count));

                // Set the location of the composite field
                compositeField.Location = new PointF(pageSize.Width - pageNumberSize.Width - 72, pageSize.Height - 45);

                // Draw the composite field on the page
                compositeField.Draw(page.Canvas);

            }

            // Save to a different PDF file
            doc.SaveToFile("AddPageNumbersToRigthCorner.pdf");

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