PM> Install-Package Spire.PDF

using Spire.Pdf;
using Spire.Pdf.Graphics;

namespace InsertImage
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a PdfDocument instance
            PdfDocument pdf = new PdfDocument();
            pdf.LoadFromFile("Input.pdf");

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

            //Load an image
            PdfImage image = PdfImage.FromFile("image.jpg");

            //Specify the width and height of the image area on the page
            float width = image.Width * 0.50f;
            float height = image.Height * 0.50f;

            //Specify the X and Y coordinates to start drawing the image
            float x = 180f;
            float y = 70f;

            //Draw the image at a specified location on the page
            page.Canvas.DrawImage(image, x, y, width, height);

            //Save the result document
            pdf.SaveToFile("AddImage.pdf", FileFormat.PDF);
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Graphics

Namespace InsertImage
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Create a PdfDocument instance
            Dim pdf As PdfDocument = New PdfDocument()
            pdf.LoadFromFile("Input.pdf")

            'Get the first page in the PDF document
            Dim page As PdfPageBase = pdf.Pages(0)

            'Load an image
            Dim image As PdfImage = PdfImage.FromFile("image.jpg")

            'Specify the width and height of the image area on the page
            Dim width As Single = image.Width * 0.50F
            Dim height As Single = image.Height * 0.50F

            'Specify the X and Y coordinates to start drawing the image
            Dim x = 180F
            Dim y = 70F

            'Draw the image at a specified location on the page
            page.Canvas.DrawImage(image, x, y, width, height)

            'Save the result document
            pdf.SaveToFile("AddImage.pdf", FileFormat.PDF)
        End Sub
    End Class
End Namespace

using Spire.Pdf;
using Spire.Pdf.Graphics;
using Spire.Pdf.Utilities;

namespace ReplaceImage
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a PdfDocument instance
            PdfDocument doc = new PdfDocument();
            //Load a PDF document
            doc.LoadFromFile("AddImage.pdf");

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

            //Load an image
            PdfImage image = PdfImage.FromFile("image1.jpg");

            //Create a PdfImageHelper instance
            PdfImageHelper imageHelper = new PdfImageHelper();
            //Get the image information from the page
            PdfImageInfo[] imageInfo = imageHelper.GetImagesInfo(page);
            //Replace the first image on the page with the loaded image
            imageHelper.ReplaceImage(imageInfo[0], image);

            //Save the result document
            doc.SaveToFile("ReplaceImage.pdf", FileFormat.PDF);
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Graphics
Imports Spire.Pdf.Utilities

Namespace ReplaceImage
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Create a PdfDocument instance
            Dim doc As PdfDocument = New PdfDocument()
            'Load a PDF document
            doc.LoadFromFile("AddImage.pdf")

            'Get the first page
            Dim page As PdfPageBase = doc.Pages(0)

            'Load an image
            Dim image As PdfImage = PdfImage.FromFile("image1.jpg")

            'Create a PdfImageHelper instance
            Dim imageHelper As PdfImageHelper = New PdfImageHelper()
            'Get the image information from the page
            Dim imageInfo As PdfImageInfo() = imageHelper.GetImagesInfo(page)
            'Replace the first image on the page with the loaded image
            imageHelper.ReplaceImage(imageInfo(0), image)

            'Save the result document
            doc.SaveToFile("ReplaceImage.pdf", FileFormat.PDF)
        End Sub
    End Class
End Namespace

using Spire.Pdf;

namespace DeleteImage
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a PdfDocument instance
            PdfDocument pdf = new PdfDocument();
            //Load a PDF document
            pdf.LoadFromFile("AddImage.pdf");

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

            //Delete the first image on the page
            PdfImageHelper imageHelper = new PdfImageHelper();
            PdfImageInfo[] imageInfos = imageHelper.GetImagesInfo(pdf.Pages[0]);
            for (int i = 0; i < imageInfos.Length; i++)
            { imageHelper.DeleteImage(imageInfos[i], true); }

            //Save the result document
            pdf.SaveToFile("DeleteImage.pdf", FileFormat.PDF);
        }
    }
}

Imports Spire.Pdf

Namespace DeleteImage
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Create a PdfDocument instance
            Dim pdf As PdfDocument = New PdfDocument()
            'Load a PDF document
            pdf.LoadFromFile("AddImage.pdf")

            'Get the first page
            Dim page As PdfPageBase = pdf.Pages(0)

            Dim imageHelper As New PdfImageHelper()
            Dim imageInfos As PdfImageInfo() = imageHelper.GetImagesInfo(pdf.Pages(0))
            For i As Integer = 0 To imageInfos.Length - 1
                imageHelper.DeleteImage(imageInfos(i), True)
            Next

            'Save the result document
            pdf.SaveToFile("DeleteImage.pdf", FileFormat.PDF)
        End Sub
    End Class
End Namespace

PM> Install-Package Spire.Doc

using Spire.Doc;

namespace PasswordProtectWordDocument
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a Document object
            Document document = new Document();

            //Load a Word file
            document.LoadFromFile(@"C:\Users\Administrator\Desktop\test.docx");

            //Encrypt the document with a password
            document.Encrypt("open-psd");

            //Save the document to another Word file
            document.SaveToFile("Encryption.docx", FileFormat.Docx);
        }
    }
}

Imports Spire.Doc
 
Namespace PasswordProtectWordDocument
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a Document object
            Dim document As Document =  New Document() 
 
            'Load a Word file
            document.LoadFromFile("C:\Users\Administrator\Desktop\test.docx")
 
            'Encrypt the document with a password
            document.Encrypt("open-psd")
 
            'Save the document to another Word file
            document.SaveToFile("Encryption.docx", FileFormat.Docx)
        End Sub
    End Class
End Namespace

using Spire.Doc;

namespace ChangeDocumentPermission
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a Document object
            Document document = new Document(); 

            //Load a Word document
            document.LoadFromFile(@"C:\Users\Administrator\Desktop\sample.docx");

            //Set the document permission and set the permission password
            document.Protect(ProtectionType.AllowOnlyFormFields, "permission-psd");

            //Save the document to another Word file
            document.SaveToFile("Permission.docx");
        }
    }
}

Imports Spire.Doc
 
Namespace ChangeDocumentPermission
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a Document object
            Dim document As Document =  New Document() 
 
            'Load a Word document
            document.LoadFromFile("C:\Users\Administrator\Desktop\sample.docx")
 
            'Set the document permission and set the permission password
            document.Protect(ProtectionType.AllowOnlyFormFields, "permission-psd")
 
            'Save the document to another Word file
            document.SaveToFile("Permission.docx")
        End Sub
    End Class
End Namespace

using Spire.Doc;

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

            //Load a Word document
            doc.LoadFromFile(@"C:\Users\Administrator\Desktop\sample.docx");

            //Set editing restriction as "AllowOnlyFormFields"
            doc.Protect(ProtectionType.AllowOnlyFormFields, "permissionPsd");

            //Unprotect section 2
            doc.Sections[1].ProtectForm = false;

            //Save the document to another Word file
            doc.SaveToFile("ProtectSection.docx");
        }
    }
}

Imports Spire.Doc
 
Namespace ProtectSpecificSection
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a Document object
            Document doc  =  New Document()
 
            'Load a Word document
            doc.LoadFromFile("C:\Users\Administrator\Desktop\sample.docx")
 
            'Set editing restriction as " AllowOnlyFormFields"
            doc.Protect(ProtectionType.AllowOnlyFormFields, "permissionPsd")
 
            'Unprotect section 2
            doc.Sections(1).ProtectForm = False
 
            'Save the document to another Word file
            doc.SaveToFile("ProtectSection.docx")
        End Sub
    End Class
End Namespace

using Spire.Doc;

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

            //Load a Word document
            doc.LoadFromFile(@"C:\Users\Administrator\Desktop\sample.docx");

            //Get custom document properties 
            CustomDocumentProperties customProperties = doc.CustomDocumentProperties;

            //Add "_MarkAsFinal" property to the document
            customProperties.Add("_MarkAsFinal", true);

            //Save the document to another Word file
            doc.SaveToFile("MarkAsFinal.docx");
        }
    }
}

Imports Spire.Doc
 
Namespace MarkAsFinal
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a Document object
            Document doc  =  New Document()
 
            'Load a Word document
            doc.LoadFromFile("C:\Users\Administrator\Desktop\sample.docx")
 
            'Get custom document properties 
            Dim customProperties As CustomDocumentProperties =  doc.CustomDocumentProperties 
 
            'Add "_MarkAsFinal" property to the document
            customProperties.Add("_MarkAsFinal", True)
 
            'Save the document to another Word file
            doc.SaveToFile("MarkAsFinal.docx")
        End Sub
    End Class
End Namespace

using Spire.Doc;

namespace RemovePassword
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a Document object
            Document document = new Document();

            //Load an encrypted Word document
            document.LoadFromFile(@"C:\Users\Administrator\Desktop\Encryption.docx", FileFormat.Docx, "open-psd");

            //Remove encryption
            document.RemoveEncryption();

            //Save the document to another Word file
            document.SaveToFile("Decryption.docx", FileFormat.Docx);
        }
    }
}

Imports Spire.Doc
 
Namespace RemovePassword
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a Document object
            Dim document As Document =  New Document() 
 
            'Load an encrypted Word document
            document.LoadFromFile("C:\Users\Administrator\Desktop\Encryption.docx", FileFormat.Docx, "open-psd")
 
            'Remove encryption
            document.RemoveEncryption()
 
            'Save the document to another Word file
            document.SaveToFile("Decryption.docx", FileFormat.Docx)
        End Sub
    End Class
End Namespace