The sample demonstrates how to merge multiple PDF documents to one PDF document.

(NO screenshot)

using System;
using Spire.Pdf;

namespace MergeDocuments
{
    class Program
    {
        static void Main(string[] args)
        {
            //pdf document list
            String[] files = new String[]
            {
                @"Sample3.pdf",
                @"Sample2.pdf",
                @"Sample1.pdf"
            };
            //open pdf documents            
            PdfDocument[] docs = new PdfDocument[files.Length];
            for (int i = 0; i < files.Length; i++)
            {
                docs[i] = new PdfDocument(files[i]);
            }

            //append document
            docs[0].AppendPage(docs[1]);

            //import page
            for (int i = 0; i < docs[2].Pages.Count; i = i + 2)
            {
                docs[0].InsertPage(docs[2], i);
            }

            //Save pdf file.
            docs[0].SaveToFile("MergeDocuments.pdf");

            //close
            foreach (PdfDocument doc in docs)
            {
                doc.Close();
            }

            //Launching the Pdf file.
            System.Diagnostics.Process.Start("MergeDocuments.pdf");
        }
    }
}

Imports Spire.Pdf

Namespace MergeDocuments
    Friend Class Program
        Shared Sub Main(ByVal args() As String)
            'pdf document list
            Dim files() As String = {"Sample3.pdf", "Sample2.pdf", "Sample1.pdf"}
            'open pdf documents            
            Dim docs(files.Length - 1) As PdfDocument
            For i As Integer = 0 To files.Length - 1
                docs(i) = New PdfDocument(files(i))
            Next i

            'append document
            docs(0).AppendPage(docs(1))

            'import page
            For i As Integer = 0 To docs(2).Pages.Count - 1 Step 2
                docs(0).InsertPage(docs(2), i)
            Next i

            'Save pdf file.
            docs(0).SaveToFile("MergeDocuments.pdf")

            'close
            For Each doc As PdfDocument In docs
                doc.Close()
            Next doc

            'Launching the Pdf file.
            Process.Start("MergeDocuments.pdf")
        End Sub

    End Class
End Namespace

The sample demonstrates how to extract images and text from PDF document.

(NO screenshot)

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Text;
using Spire.Pdf;

namespace Extraction
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a pdf document.
            PdfDocument doc = new PdfDocument();
            doc.LoadFromFile(@"Sample2.pdf");

            StringBuilder buffer = new StringBuilder();
            IList<Image> images = new List<Image>();

            foreach (PdfPageBase page in doc.Pages)
            {
                buffer.Append(page.ExtractText());
                foreach (Image image in page.ExtractImages())
                {
                    images.Add(image);
                }
            }

            doc.Close();

            //save text
            String fileName = "TextInPdf.txt";
            File.WriteAllText(fileName, buffer.ToString());

            //save image
            int index = 0;
            foreach (Image image in images)
            {
                String imageFileName
                    = String.Format("Image-{0}.png", index++);
                image.Save(imageFileName, ImageFormat.Png);
            }

            //Launching the Text file.
            System.Diagnostics.Process.Start(fileName);
        }

    }
}

Imports System.Collections.Generic
Imports System.Drawing
Imports System.Drawing.Imaging
Imports System.IO
Imports System.Text
Imports Spire.Pdf

Namespace Extraction
    Friend Class Program
        Shared Sub Main(ByVal args() As String)
            'Create a pdf document.
            Dim doc As New PdfDocument()
            doc.LoadFromFile("Sample2.pdf")

            Dim buffer As New StringBuilder()
            Dim images As IList(Of Image) = New List(Of Image)()

            For Each page As PdfPageBase In doc.Pages
                buffer.Append(page.ExtractText())
                For Each image As Image In page.ExtractImages()
                    images.Add(image)
                Next image
            Next page

            doc.Close()

            'save text
            Dim fileName As String = "TextInPdf.txt"
            File.WriteAllText(fileName, buffer.ToString())

            'save image
            Dim index As Integer = 0
            For Each image As Image In images
                Dim imageFileName As String = String.Format("Image-{0}.png", index)
                index += 1
                image.Save(imageFileName, ImageFormat.Png)
            Next image

            'Launching the Text file.
            Process.Start(fileName)
        End Sub

    End Class
End Namespace

The sample demonstrates how to convert a PDF document to a booklet.

Download Booklet.pdf

using System;
using Spire.Pdf;

namespace Booklet
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a pdf document.
            PdfDocument doc = new PdfDocument();

            String srcPdf = @"Sample2.pdf";
            float width = PdfPageSize.A4.Width * 2;
            float height = PdfPageSize.A4.Height;
            doc.CreateBooklet(srcPdf, width, height, true);

            //Save pdf file.
            doc.SaveToFile("Booklet.pdf");
            doc.Close();

            //Launching the Pdf file.
            System.Diagnostics.Process.Start("Booklet.pdf");
        }
    }
}

Imports Spire.Pdf

Namespace Booklet
    Friend Class Program
        Shared Sub Main(ByVal args() As String)
            'Create a pdf document.
            Dim doc As New PdfDocument()

            Dim srcPdf As String = "Sample2.pdf"
            Dim width As Single = PdfPageSize.A4.Width * 2
            Dim height As Single = PdfPageSize.A4.Height
            doc.CreateBooklet(srcPdf, width, height, True)

            'Save pdf file.
            doc.SaveToFile("Booklet.pdf")
            doc.Close()

            'Launching the Pdf file.
            Process.Start("Booklet.pdf")
        End Sub
    End Class
End Namespace