using System.IO;
using Spire.PdfViewer.Forms;

Imports System.IO
Imports Spire.PdfViewer.Forms

private void Form1_Load(object sender, EventArgs e)
        {
            string pdfDoc = @"D:\michelle\e-iceblue\Spire.PDFViewer\Demos\Data\PDFViewer.pdf";
            if (File.Exists(pdfDoc))
            {
                this.pdfDocumentViewer1.LoadFromFile(pdfDoc);
            }
        }
private void btnOpen_Click(object sender, EventArgs e)
       {
            OpenFileDialog dialog = new OpenFileDialog();
            dialog.Filter = "PDF document (*.pdf)|*.pdf";
            DialogResult result = dialog.ShowDialog();
            if (result == DialogResult.OK)
            {
                try
                {
                    string pdfFile = dialog.FileName;
                    this.pdfDocumentViewer1.LoadFromFile(pdfFile);
                }
                catch (Exception exe)
                {
                    MessageBox.Show(exe.Message, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }

            }
        }

Private Sub Form1_Load(sender As Object, e As EventArgs)
		Dim pdfDoc As String = "D:\michelle\e-iceblue\Spire.PDFViewer\Demos\Data\PDFViewer.pdf"
		If File.Exists(pdfDoc) Then
			Me.pdfDocumentViewer1.LoadFromFile(pdfDoc)
		End If
End Sub

Private Sub btnOpen_Click(sender As Object, e As EventArgs)
	Dim dialog As New OpenFileDialog()
	dialog.Filter = "PDF document (*.pdf)|*.pdf"
	Dim result As DialogResult = dialog.ShowDialog()
	If result = DialogResult.OK Then
		Try
			Dim pdfFile As String = dialog.FileName
		Me.pdfDocumentViewer1.LoadFromFile(pdfFile)
		Catch exe As Exception
			MessageBox.Show(exe.Message, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.[Error])

		End Try
	End If
End Sub

private void pdfDocumentViewer1_PdfLoaded(object sender, EventArgs args)
{
            this.comBoxFrom.Items.Clear();
            this.comboxTo.Items.Clear();

            int totalPage = this.pdfDocumentViewer1.PageCount;
            for (int i = 1; i <= totalPage; i++)
            {
                this.comBoxFrom.Items.Add(i.ToString());
                this.comboxTo.Items.Add(i.ToString());


            }
            this.comBoxFrom.SelectedIndex = 0;
            this.comboxTo.SelectedIndex = 0;

 }
private void btnExport_Click(object sender, EventArgs e)
 {
            if (this.pdfDocumentViewer1.PageCount > 0)
            {
                SaveFileDialog dialog = new SaveFileDialog();
                dialog.Filter = "JPG Format(*.jpg)|*.jpg|BMP Format(*.bmp)|*.bmp|PNG Format(*.png)|*.png|GIF Format(*.gif)|*.gif";
                DialogResult result = dialog.ShowDialog();
                string fileName = dialog.FileName;
                if (result == DialogResult.OK)
                {

                    int currentPage = this.pdfDocumentViewer1.CurrentPageNumber;
                    Bitmap image = this.pdfDocumentViewer1.SaveAsImage(currentPage - 1);
                    image.Save(fileName);
                    MessageBox.Show("You have exported current page to an image:\n" + fileName, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Information);


                    Dictionary dictionaryImages = new Dictionary();
                    dictionaryImages.Add(fileName, image);

                    this._formImages = new FormImages();
                    this._formImages.DictionaryImages = dictionaryImages;
                    this._formImages.Show();

                  }
              }
  }

Private Sub pdfDocumentViewer1_PdfLoaded(sender As Object, args As EventArgs)
	Me.comBoxFrom.Items.Clear()
	Me.comboxTo.Items.Clear()
	Dim totalPage As Integer = Me.pdfDocumentViewer1.PageCount
	For i As Integer = 1 To totalPage
		Me.comBoxFrom.Items.Add(i.ToString())
		Me.comboxTo.Items.Add(i.ToString())
	Next
	Me.comBoxFrom.SelectedIndex = 0
	Me.comboxTo.SelectedIndex = 0
End Sub
Private Sub btnExport_Click(sender As Object, e As EventArgs)
	If Me.pdfDocumentViewer1.PageCount > 0 Then
		Dim dialog As New SaveFileDialog()
		dialog.Filter = "JPG Format(*.jpg)|*.jpg|BMP Format(*.bmp)|*.bmp|PNG Format(*.png)|*.png|GIF Format(*.gif)|*.gif"
		Dim result As DialogResult = dialog.ShowDialog()
		Dim fileName As String = dialog.FileName
		If result = DialogResult.OK Then
			Dim currentPage As Integer = Me.pdfDocumentViewer1.CurrentPageNumber
			Dim image As Bitmap = Me.pdfDocumentViewer1.SaveAsImage(currentPage - 1)
			image.Save(fileName)
			MessageBox.Show("You have exported current page to an image:" & vbLf & fileName, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Information)
			Dim dictionaryImages As New Dictionary(Of String, Image)()
			dictionaryImages.Add(fileName, image)
			Me._formImages = New FormImages()
			Me._formImages.DictionaryImages = dictionaryImages
			Me._formImages.Show()
		End If
	End If
End Sub

private void btnMultiExport_Click(object sender, EventArgs e)
{
            if (this.pdfDocumentViewer1.PageCount <= 0)
            {
                return;
            }

            int fromPage = this.comBoxFrom.SelectedIndex;
            int toPage = this.comboxTo.SelectedIndex;
            if (fromPage > toPage)
            {
                MessageBox.Show("End page number must be not less than started page number!", "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }
            else
            {
                FolderBrowserDialog dialog = new FolderBrowserDialog();


                DialogResult result = dialog.ShowDialog();
                if (result == DialogResult.OK)
                {

                    string path = dialog.SelectedPath;
                    Bitmap[] images = this.pdfDocumentViewer1.SaveAsImage(fromPage, toPage);
                    Dictionary dictionaryImages = new Dictionary();
                    for (int i = 0; i < images.Length; i++)
                    {
                        string name = "image" + (i + 1 + fromPage).ToString() + ".bmp";
                        string fileName = path + "\\" + name;
                        images[i].Save(fileName);
                        dictionaryImages.Add(fileName, images[i]);

                    }
                    string message = "You have exported " + (fromPage + 1).ToString() + "-" + (toPage + 1).ToString() + " pages as images to:\n"
                       + path;
                    MessageBox.Show(message, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Information);

                    this._formImages = new FormImages();
                    this._formImages.DictionaryImages = dictionaryImages;
                    this._formImages.Show();

                }
            }
   }

Private Sub btnMultiExport_Click(sender As Object, e As EventArgs)
		If Me.pdfDocumentViewer1.PageCount <= 0 Then
			Return
		End If

		Dim fromPage As Integer = Me.comBoxFrom.SelectedIndex
		Dim toPage As Integer = Me.comboxTo.SelectedIndex
		If fromPage > toPage Then
			MessageBox.Show("End page number must be not less than started page number!", "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Warning)
			Return
		Else
			Dim dialog As New FolderBrowserDialog()
			Dim result As DialogResult = dialog.ShowDialog()
			If result = DialogResult.OK Then
				Dim path As String = dialog.SelectedPath
				Dim images As Bitmap() = Me.pdfDocumentViewer1.SaveAsImage(fromPage, toPage)
				Dim dictionaryImages As Dictionary(Of [String], Image) = New Dictionary(Of String, Image)()
				For i As Integer = 0 To images.Length - 1
					Dim name As String = "image" & (i + 1 + fromPage).ToString() & ".bmp"
					Dim fileName As String = path & "\" & name
					images(i).Save(fileName)
					dictionaryImages.Add(fileName, images(i))
				Next
				Dim message As String = "You have exported " & (fromPage + 1).ToString() & "-" & (toPage + 1).ToString() & " pages as images to:" & vbLf & path
				MessageBox.Show(message, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Information)
				Me._formImages = New FormImages()
				Me._formImages.DictionaryImages = dictionaryImages
				Me._formImages.Show()
			End If
		End If
	End Sub

using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Windows.Forms;
using Spire.PdfViewer.Forms;

namespace  pdf2images1
{
    public partial class FormImages : Form
    {

        private Dictionary _dictionaryImags;

        public Dictionary DictionaryImages
        {
            get { return this._dictionaryImags; }
            set
            {
                this._dictionaryImags = value;
                this.ViewImages();
            }
        }
        public FormImages()
        {
            InitializeComponent();
        }

        public void ViewImages()
        {
            if (this.DictionaryImages != null && this.DictionaryImages.Count > 0)
            {
                this.panelImages1.Controls.Clear();
                String image_name = "";
                int panelHeight = 0;
                int panelWidth = 0;

                foreach (KeyValuePair pair in this.DictionaryImages)
                {
                    image_name = pair.Key;

                    Panel panelImage = new Panel();
                    panelImage.AutoSize = true;


                    PictureBox ptrBox = new PictureBox();
                    ptrBox.Height = 150;
                    ptrBox.Width = 200;

                    ptrBox.SizeMode = PictureBoxSizeMode.Zoom;

                    ptrBox.Image = pair.Value;
                    ptrBox.Cursor = Cursors.Hand;

                    panelImage.Controls.Add(ptrBox);

                    LinkLabel lbl = new LinkLabel();
                    String imageName = Path.GetFileName(pair.Key);
                    lbl.Text = imageName;
                    int x = (Int32)(ptrBox.Width / 2 - lbl.Width / 2);
                    int y = ptrBox.Height;
                    lbl.Left = x;
                    lbl.Top = y;
                    panelImage.Controls.Add(lbl);

                    this.panelImages1.Controls.Add(panelImage);

                    this.SetClickEventHandler(ptrBox, lbl, image_name);
                    panelHeight = panelImage.Height;
                    panelWidth = panelImage.Width;

                }
                int nimages = this._dictionaryImags.Count;
                if (nimages >= 4)
                {

                    int n = (Int32)Math.Ceiling(Math.Sqrt(nimages));

                    this.Width = panelWidth * n + 20 * (n - 1) + 40;
                    this.Height = panelHeight * n + 20 * (n - 1) + 40;
                }
            }
        }
        private void SetClickEventHandler(PictureBox ptrBox, LinkLabel lbl, string imageName)
        {
            ptrBox.Click += new EventHandler(delegate(Object sender, EventArgs args)
            {
                System.Diagnostics.Process process = new System.Diagnostics.Process();
                System.Diagnostics.ProcessStartInfo info = new System.Diagnostics.ProcessStartInfo(imageName);
                process.StartInfo = info;
                process.Start();
            });

            lbl.Click += new EventHandler(delegate(Object sender, EventArgs args)
            {
                System.Diagnostics.Process process = new System.Diagnostics.Process();
                System.Diagnostics.ProcessStartInfo info = new System.Diagnostics.ProcessStartInfo(imageName);
                process.StartInfo = info;
                process.Start();
            });

        }
    }
}

Imports System.Collections.Generic
Imports System.Drawing
Imports System.IO
Imports System.Windows.Forms

Namespace pdf2images1
	Public Partial Class FormImages
		Inherits Form
		Private _dictionaryImags As Dictionary(Of [String], Image)
		Public Property DictionaryImages() As Dictionary(Of [String], Image)
			Get
				Return Me._dictionaryImags
			End Get
			Set
				Me._dictionaryImags = value
				Me.ViewImages()
			End Set
		End Property
		Public Sub New()
			InitializeComponent()
		End Sub

		Public Sub ViewImages()
			If Me.DictionaryImages IsNot Nothing AndAlso Me.DictionaryImages.Count > 0 Then
				Me.panelImages1.Controls.Clear()
				Dim image_name As [String] = ""
				Dim panelHeight As Integer = 0
				Dim panelWidth As Integer = 0

				For Each pair As KeyValuePair(Of [String], Image) In Me.DictionaryImages
					image_name = pair.Key

					Dim panelImage As New Panel()
					panelImage.AutoSize = True


					Dim ptrBox As New PictureBox()
					ptrBox.Height = 150
					ptrBox.Width = 200

					ptrBox.SizeMode = PictureBoxSizeMode.Zoom

					ptrBox.Image = pair.Value
					ptrBox.Cursor = Cursors.Hand

					panelImage.Controls.Add(ptrBox)

					Dim lbl As New LinkLabel()
					Dim imageName As [String] = Path.GetFileName(pair.Key)
					lbl.Text = imageName
					Dim x As Integer = CType(ptrBox.Width \ 2 - lbl.Width \ 2, Int32)
					Dim y As Integer = ptrBox.Height
					lbl.Left = x
					lbl.Top = y
					panelImage.Controls.Add(lbl)

					Me.panelImages1.Controls.Add(panelImage)

					Me.SetClickEventHandler(ptrBox, lbl, image_name)
					panelHeight = panelImage.Height

					panelWidth = panelImage.Width
				Next
				Dim nimages As Integer = Me._dictionaryImags.Count
				If nimages >= 4 Then

					Dim n As Integer = CType(Math.Truncate(Math.Ceiling(Math.Sqrt(nimages))), Int32)

					Me.Width = panelWidth * n + 20 * (n - 1) + 40
					Me.Height = panelHeight * n + 20 * (n - 1) + 40
				End If
			End If
		End Sub
		Private Sub SetClickEventHandler(ptrBox As PictureBox, lbl As LinkLabel, imageName As String)
			AddHandler ptrBox.Click, New EventHandler(Function(sender As [Object], args As EventArgs) Do
				Dim process As New System.Diagnostics.Process()
				Dim info As New System.Diagnostics.ProcessStartInfo(imageName)
				process.StartInfo = info
				process.Start()
			End Function)

			AddHandler lbl.Click, New EventHandler(Function(sender As [Object], args As EventArgs) Do
				Dim process As New System.Diagnostics.Process()
				Dim info As New System.Diagnostics.ProcessStartInfo(imageName)
				process.StartInfo = info
				process.Start()
			End Function)
		End Sub
	End Class
End Namespace

using System;
using System.Drawing;
using System.IO;
using System.Windows.Forms;
using Spire.PdfViewer.Forms;

Imports System.Drawing
Imports System.IO
Imports System.Windows.Forms
Imports Spire.PdfViewer.Forms

viewer = new PdfDocumentViewer();
viewer.LoadFromFile(@"D:\michelle\e-iceblue\Spire.PDFViewer\Demos\Data\PDFViewer.pdf");

viewer = New PdfDocumentViewer()
viewer.LoadFromFile("D:\michelle\e-iceblue\Spire.PDFViewer\Demos\Data\PDFViewer.pdf")

            //form and child components
            Form mainForm = new Form();
            mainForm.Text = "Spire.PdfView Demo - Export";
            mainForm.Size = new System.Drawing.Size(800, 600);
            mainForm.StartPosition = FormStartPosition.CenterScreen;

            TableLayoutPanel table = new TableLayoutPanel();
            table.ColumnCount = 3;
            table.ColumnStyles.Add(new ColumnStyle(SizeType.Percent, 50));
            table.ColumnStyles.Add(new ColumnStyle(SizeType.Absolute, 20));
            table.ColumnStyles.Add(new ColumnStyle(SizeType.Percent, 50));
            table.RowCount = 2;
            table.RowStyles.Add(new RowStyle(SizeType.Percent, 100));
            table.RowStyles.Add(new RowStyle(SizeType.Absolute, 30));

            table.Controls.Add(viewer, 0, 0);
            table.SetColumnSpan(viewer, 3);
            viewer.Dock = DockStyle.Fill;

            //Export current page to one image
            Button button = new Button();
            button.Text = "Export to one image";
            button.Size = new Size(180, 24);
            button.TextAlign = ContentAlignment.MiddleCenter;
            table.Controls.Add(button, 0, 1);
            button.Dock = DockStyle.Right;
            button.Click += ExportToOneImage;

            //Export current pdf document to multiple images
            button = new Button();
            button.Text = "Export to multiple images";
            button.Size = new Size(180, 24);
            button.TextAlign = ContentAlignment.MiddleCenter;
            table.Controls.Add(button, 2, 1);
            button.Dock = DockStyle.Left;
            button.Click += ExportToMultipleImages;

            mainForm.Controls.Add(table);
            table.Dock = DockStyle.Fill;

            Application.Run(mainForm);

	'form and child components
	Dim mainForm As New Form()
	mainForm.Text = "Spire.PdfView Demo - Export"
	mainForm.Size = New System.Drawing.Size(800, 600)
	mainForm.StartPosition = FormStartPosition.CenterScreen

	Dim table As New TableLayoutPanel()
	table.ColumnCount = 3
	table.ColumnStyles.Add(New ColumnStyle(SizeType.Percent, 50))
	table.ColumnStyles.Add(New ColumnStyle(SizeType.Absolute, 20))
	table.ColumnStyles.Add(New ColumnStyle(SizeType.Percent, 50))
	table.RowCount = 2
	table.RowStyles.Add(New RowStyle(SizeType.Percent, 100))
	table.RowStyles.Add(New RowStyle(SizeType.Absolute, 30))

	table.Controls.Add(viewer, 0, 0)
	table.SetColumnSpan(viewer, 3)
	viewer.Dock = DockStyle.Fill

	'Export current page to one image
	Dim button As New Button()
	button.Text = "Export to one image"
	button.Size = New Size(180, 24)
	button.TextAlign = ContentAlignment.MiddleCenter
	table.Controls.Add(button, 0, 1)
	button.Dock = DockStyle.Right
	AddHandler button.Click, AddressOf ExportToOneImage

	'Export current pdf document to multiple images
	button = New Button()
	button.Text = "Export to multiple images"
	button.Size = New Size(180, 24)
	button.TextAlign = ContentAlignment.MiddleCenter
	table.Controls.Add(button, 2, 1)
	button.Dock = DockStyle.Left
	AddHandler button.Click, AddressOf ExportToMultipleImages

	mainForm.Controls.Add(table)
	table.Dock = DockStyle.Fill

	Application.Run(mainForm)

private static void ExportToOneImage(object sender, EventArgs e)
      {
         if (viewer.PageCount > 0)
          {
                SaveFileDialog dialog = new SaveFileDialog();
                dialog.Filter = "PNG Format(*.png)|*.png";
                if (dialog.ShowDialog() == DialogResult.OK)
                {
                    int currentPage = viewer.CurrentPageNumber;
                    Bitmap image = viewer.SaveAsImage(currentPage - 1);
                    image.Save(dialog.FileName);
                    MessageBox.Show("You have exported current page to an image:\n" + dialog.FileName, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
            }
        }

Private Shared Sub ExportToOneImage(sender As Object, e As EventArgs)
	If viewer.PageCount > 0 Then
		Dim dialog As New SaveFileDialog()
		dialog.Filter = "PNG Format(*.png)|*.png"
		If dialog.ShowDialog() = DialogResult.OK Then
			Dim currentPage As Integer = viewer.CurrentPageNumber
			Dim image As Bitmap = viewer.SaveAsImage(currentPage - 1)
			image.Save(dialog.FileName)
			MessageBox.Show("You have exported current page to an image:" & vbLf & dialog.FileName, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Information)
		End If
	End If
End Sub

private static void ExportToMultipleImages(object sender, EventArgs e)
        {
            if (viewer.PageCount > 0)
            {
                FolderBrowserDialog dialog = new FolderBrowserDialog();
                if (dialog.ShowDialog() == DialogResult.OK)
                {
                    int currentPage = viewer.CurrentPageNumber;
                    Bitmap[] images = viewer.SaveAsImage(0, currentPage - 1);
                    for (int i = 0; i < images.Length; i++)
                    {
                        String fileName = Path.Combine(dialog.SelectedPath, String.Format("PDFViewer-{0}.png", i));
                        images[i].Save(fileName);
                    }
                    string message = "You have exported 1" + "-" + currentPage.ToString() + " pages as images to:\n" + dialog.SelectedPath;
                    MessageBox.Show(message, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
            }
        }

Private Shared Sub ExportToMultipleImages(sender As Object, e As EventArgs)
	If viewer.PageCount > 0 Then
		Dim dialog As New FolderBrowserDialog()
		If dialog.ShowDialog() = DialogResult.OK Then
			Dim currentPage As Integer = viewer.CurrentPageNumber
			Dim images As Bitmap() = viewer.SaveAsImage(0, currentPage - 1)
			For i As Integer = 0 To images.Length - 1
				Dim fileName As [String] = Path.Combine(dialog.SelectedPath, [String].Format("PDFViewer-{0}.png", i))
				images(i).Save(fileName)
			Next
			Dim message As String = "You have exported 1" & "-" & currentPage.ToString() & " pages as images to:" & vbLf & dialog.SelectedPath
			MessageBox.Show(message, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Information)
		End If
	End If
End Sub

using System.IO;
using System.Windows.Forms;
using Spire.PdfViewer.Forms;

Imports System.IO
Imports System.Windows.Forms
Imports Spire.PdfViewer.Forms

namespace pdfzoom
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        //private bool _isZoomout = true;

        private int _zoom = 100;
        private bool _isZoomDynamic = false;

        private void Form1_Load(object sender, EventArgs e)
        {
            string pdfDoc = @"D:\michelle\e-iceblue\Spire.PDFViewer\Demos\Data\PDFViewer.pdf";
            if (File.Exists(pdfDoc))
            {
                this.pdfDocumentViewer1.LoadFromFile(pdfDoc);
            }

            //add zoom values to combox
            int[] intZooms = new Int32[] { 25, 50, 75, 100, 125, 150, 200, 300, 400, 500, 600, 700, 800, 900, 1000 };
            foreach (int zoom in intZooms)
            {
                this.comBoxZoom.Items.Add(zoom.ToString());
            }
            this.comBoxZoom.SelectedIndex = 3;

            //pdfDocumentViewer mouseWheel event

            this.pdfDocumentViewer1.MouseWheel += new MouseEventHandler(this.pdfDocumentViewer1_MouseWheel);
            this.pdfDocumentViewer1.LostFocus += new EventHandler(this.pdfDocumentViewer_LostFocus);

        }
        private void pdfDocumentViewer_LostFocus(Object sender, EventArgs args)
        {
            this._isZoomDynamic = false;
            this._zoom = 100;
        }

        private void pdfDocumentViewer1_MouseWheel(Object sender, MouseEventArgs args)
        {
            if (this._isZoomDynamic)
            {
                int wheelValue = (Int32)args.Delta / 24;


                this._zoom += wheelValue;

                if (this._zoom < 0)
                    this._zoom = 0;
                this.pdfDocumentViewer1.ZoomTo(this._zoom);
            }

        }

        private void btnOPen_Click(object sender, EventArgs e)
        {
            OpenFileDialog dialog = new OpenFileDialog();
            dialog.Filter = "PDF document (*.pdf)|*.pdf";

            DialogResult result = dialog.ShowDialog();
            if (result == DialogResult.OK)
            {
                try
                {
                    string pdfFile = dialog.FileName;
                    this.pdfDocumentViewer1.LoadFromFile(pdfFile);

                }
                catch (Exception exe)
                {
                    MessageBox.Show(exe.Message, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }

            }
        }

        private void comBoxZoom_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (this.pdfDocumentViewer1.PageCount > 0)
            {
                int zoomValue = Int32.Parse(this.comBoxZoom.SelectedItem.ToString());
                this.pdfDocumentViewer1.ZoomTo(zoomValue);
            }
        }

        private void btnZoomOut_Click(object sender, EventArgs e)
        {
            if (this.pdfDocumentViewer1.PageCount > 0)
            {
                int delta = 10;
                this._zoom += delta;
                this.pdfDocumentViewer1.ZoomTo(this._zoom);
            }
        }

        private void btnZoonIn_Click(object sender, EventArgs e)
        {
            if (this.pdfDocumentViewer1.PageCount > 0)
            {
                int delta = 5;
                this._zoom -= delta;
                if (this._zoom < 0)
                    this._zoom = 0;
                this.pdfDocumentViewer1.ZoomTo(this._zoom);
            }
        }

        private void btnActural_Click(object sender, EventArgs e)
        {
            this._zoom = 100;
            this._isZoomDynamic = false;
            this.btnDynamic.Text = "Zoom Dynamic";
            if (this.pdfDocumentViewer1.PageCount > 0)
            {
                this.pdfDocumentViewer1.ZoomTo(100);
                this.comBoxZoom.SelectedIndex = 3;
            }
        }

        private void btnFitPage_Click(object sender, EventArgs e)
        {
            if (this.pdfDocumentViewer1.PageCount > 0)
            {
                this.pdfDocumentViewer1.ZoomTo(ZoomMode.FitPage);
            }
        }

        private void btnFitWidth_Click(object sender, EventArgs e)
        {
            if (this.pdfDocumentViewer1.PageCount > 0)
            {
                this.pdfDocumentViewer1.ZoomTo(ZoomMode.FitWidth);
            }
        }

        private void btnDynamic_Click(object sender, EventArgs e)
        {
            this._isZoomDynamic = !this._isZoomDynamic;
            if (this._isZoomDynamic)
            {

                this.btnDynamic.Text = "Cancel dynamic zoom";
                this.btnDynamic.ToolTipText = "Cancel dynamic zoom";
            }

            else
            {
                this.btnDynamic.Text = "Zoom dynamic";
                this.btnDynamic.ToolTipText = "Zoom dynamic";
            }

        }

        private void pdfDocumentViewer1_PdfLoaded(object sender, EventArgs args)
        {
            this.btnDynamic.Enabled = true;
            this.comBoxPages.Items.Clear();
            int totalPage = this.pdfDocumentViewer1.PageCount;

            for (int i = 1; i <= totalPage; i++)
            {
                this.comBoxPages.Items.Add(i.ToString());
            }

            this.comBoxPages.SelectedIndex = 0;
        }

        private void pdfDocumentViewer1_PageNumberChanged(object sender, EventArgs args)
        {
            if (this.comBoxPages.Items.Count <= 0)
                return;
            if (this.pdfDocumentViewer1.CurrentPageNumber != this.comBoxPages.SelectedIndex + 1)
            {
                this.comBoxPages.SelectedIndex = this.pdfDocumentViewer1.CurrentPageNumber - 1;
            }
        }

        private void comBoxPages_SelectedIndexChanged(object sender, EventArgs e)
        {
            int soucePage = this.pdfDocumentViewer1.CurrentPageNumber;
            int targetPage = this.comBoxPages.SelectedIndex + 1;
            if (soucePage != targetPage)
            {
                this.pdfDocumentViewer1.GoToPage(targetPage);
            }
        }

        private void comBoxPages_Click(object sender, EventArgs e)
        {

        }

    }
}

Namespace pdfzoom
	Public Partial Class Form1
		Inherits Form
		Public Sub New()
			InitializeComponent()
		End Sub

		'private bool _isZoomout = true;

		Private _zoom As Integer = 100
		Private _isZoomDynamic As Boolean = False

		Private Sub Form1_Load(sender As Object, e As EventArgs)
			Dim pdfDoc As String = "D:\michelle\e-iceblue\Spire.PDFViewer\Demos\Data\PDFViewer.pdf"
			If File.Exists(pdfDoc) Then
				Me.pdfDocumentViewer1.LoadFromFile(pdfDoc)
			End If

			'add zoom values to combox
			Dim intZooms As Integer() = New Int32() {25, 50, 75, 100, 125, 150, _
				200, 300, 400, 500, 600, 700, _
				800, 900, 1000}
			For Each zoom As Integer In intZooms
				Me.comBoxZoom.Items.Add(zoom.ToString())
			Next
			Me.comBoxZoom.SelectedIndex = 3

			'pdfDocumentViewer mouseWheel event

			Me.pdfDocumentViewer1.MouseWheel += New MouseEventHandler(AddressOf Me.pdfDocumentViewer1_MouseWheel)
			Me.pdfDocumentViewer1.LostFocus += New EventHandler(AddressOf Me.pdfDocumentViewer_LostFocus)

		End Sub
		Private Sub pdfDocumentViewer_LostFocus(sender As [Object], args As EventArgs)
			Me._isZoomDynamic = False
			Me._zoom = 100
		End Sub

		Private Sub pdfDocumentViewer1_MouseWheel(sender As [Object], args As MouseEventArgs)
			If Me._isZoomDynamic Then
				Dim wheelValue As Integer = DirectCast(args.Delta, Int32) / 24


				Me._zoom += wheelValue

				If Me._zoom < 0 Then
					Me._zoom = 0
				End If
				Me.pdfDocumentViewer1.ZoomTo(Me._zoom)
			End If

		End Sub

		Private Sub btnOPen_Click(sender As Object, e As EventArgs)
			Dim dialog As New OpenFileDialog()
			dialog.Filter = "PDF document (*.pdf)|*.pdf"

			Dim result As DialogResult = dialog.ShowDialog()
			If result = DialogResult.OK Then
				Try
					Dim pdfFile As String = dialog.FileName

					Me.pdfDocumentViewer1.LoadFromFile(pdfFile)
				Catch exe As Exception
					MessageBox.Show(exe.Message, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.[Error])

				End Try
			End If
		End Sub

		Private Sub comBoxZoom_SelectedIndexChanged(sender As Object, e As EventArgs)
			If Me.pdfDocumentViewer1.PageCount > 0 Then
				Dim zoomValue As Integer = Int32.Parse(Me.comBoxZoom.SelectedItem.ToString())
				Me.pdfDocumentViewer1.ZoomTo(zoomValue)
			End If
		End Sub

		Private Sub btnZoomOut_Click(sender As Object, e As EventArgs)
			If Me.pdfDocumentViewer1.PageCount > 0 Then
				Dim delta As Integer = 10
				Me._zoom += delta
				Me.pdfDocumentViewer1.ZoomTo(Me._zoom)
			End If
		End Sub

		Private Sub btnZoonIn_Click(sender As Object, e As EventArgs)
			If Me.pdfDocumentViewer1.PageCount > 0 Then
				Dim delta As Integer = 5
				Me._zoom -= delta
				If Me._zoom < 0 Then
					Me._zoom = 0
				End If
				Me.pdfDocumentViewer1.ZoomTo(Me._zoom)
			End If
		End Sub

		Private Sub btnActural_Click(sender As Object, e As EventArgs)
			Me._zoom = 100
			Me._isZoomDynamic = False
			Me.btnDynamic.Text = "Zoom Dynamic"
			If Me.pdfDocumentViewer1.PageCount > 0 Then
				Me.pdfDocumentViewer1.ZoomTo(100)
				Me.comBoxZoom.SelectedIndex = 3
			End If
		End Sub

		Private Sub btnFitPage_Click(sender As Object, e As EventArgs)
			If Me.pdfDocumentViewer1.PageCount > 0 Then
				Me.pdfDocumentViewer1.ZoomTo(ZoomMode.FitPage)
			End If
		End Sub

		Private Sub btnFitWidth_Click(sender As Object, e As EventArgs)
			If Me.pdfDocumentViewer1.PageCount > 0 Then
				Me.pdfDocumentViewer1.ZoomTo(ZoomMode.FitWidth)
			End If
		End Sub

		Private Sub btnDynamic_Click(sender As Object, e As EventArgs)
			Me._isZoomDynamic = Not Me._isZoomDynamic
			If Me._isZoomDynamic Then

				Me.btnDynamic.Text = "Cancel dynamic zoom"
				Me.btnDynamic.ToolTipText = "Cancel dynamic zoom"
			Else

				Me.btnDynamic.Text = "Zoom dynamic"
				Me.btnDynamic.ToolTipText = "Zoom dynamic"
			End If

		End Sub

		Private Sub pdfDocumentViewer1_PdfLoaded(sender As Object, args As EventArgs)
			Me.btnDynamic.Enabled = True
			Me.comBoxPages.Items.Clear()
			Dim totalPage As Integer = Me.pdfDocumentViewer1.PageCount

			For i As Integer = 1 To totalPage
				Me.comBoxPages.Items.Add(i.ToString())
			Next

			Me.comBoxPages.SelectedIndex = 0
		End Sub

		Private Sub pdfDocumentViewer1_PageNumberChanged(sender As Object, args As EventArgs)
			If Me.comBoxPages.Items.Count <= 0 Then
				Return
			End If
			If Me.pdfDocumentViewer1.CurrentPageNumber <> Me.comBoxPages.SelectedIndex + 1 Then
				Me.comBoxPages.SelectedIndex = Me.pdfDocumentViewer1.CurrentPageNumber - 1
			End If
		End Sub

		Private Sub comBoxPages_SelectedIndexChanged(sender As Object, e As EventArgs)
			Dim soucePage As Integer = Me.pdfDocumentViewer1.CurrentPageNumber
			Dim targetPage As Integer = Me.comBoxPages.SelectedIndex + 1
			If soucePage <> targetPage Then
				Me.pdfDocumentViewer1.GoToPage(targetPage)
			End If
		End Sub

		Private Sub comBoxPages_Click(sender As Object, e As EventArgs)

		End Sub

	End Class
End Namespace