Manages the thumbnails in this document viewer.
public DocumentViewerThumbnails Thumbnails { get; }
The DocumentViewerThumbnails object that manages the thumbnails in this document viewer.
This class manages the thumbnail image of the pages in the current LEADDocument set in the document viewer.
The class creates an instance of ImageViewer for viewing the thumbnails. The thumbnail images are loaded in a background thread to keep the application user interface responsive.
The class also handles the user interactions with the thumbnails, such as clicking on a thumbnail to move the view to the specified page.
Refer to DocumentViewerThumbnails for more information.
using Leadtools;using Leadtools.Controls;using Leadtools.Document;using Leadtools.Document.Viewer;using Leadtools.Codecs;using Leadtools.Caching;using Leadtools.Annotations.Engine;using Leadtools.Ocr;public void DocumentViewer_Example(){// New Form to be used as our applicationvar form = new MyForm();form.ShowDialog();}class MyForm : Form{public MyForm(){this.Size = new Size(800, 800);this.Text = "LEADTOOLS Document Viewer Example";}protected override void OnLoad(EventArgs e){if (!DesignMode){// Init OCR. This is optional and not required for the PDF document we are loading.// But if image documents are loaded and text functionality is used, then we need OCR_ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD);_ocrEngine.Startup(null, null, null, @"C:\LEADTOOLS22\Bin\Common\OcrLEADRuntime");Init();}base.OnLoad(e);}// Our document viewer instanceprivate DocumentViewer _documentViewer;// Optional OCR engine to use in the exampleprivate IOcrEngine _ocrEngine;private void Init(){// Initialize the user interfaceInitUI();// Init the cache. This is optional, but it can speed up viewing of large documents// if not needed, remove this sectionDocumentFactory.Cache = new FileCache();// Init the document viewer, pass along the panelsvar createOptions = new DocumentViewerCreateOptions{// The middle panel for the viewViewContainer = this.Controls.Find("middlePanel", false)[0],// The left panel for the thumbnailsThumbnailsContainer = this.Controls.Find("leftPanel", false)[0],// The right panel is for bookmarksBookmarksContainer = this.Controls.Find("rightPanel", false)[0],// Not using annotations for nowUseAnnotations = false};// Create the document viewer_documentViewer = DocumentViewerFactory.CreateDocumentViewer(createOptions);// We prefer SVG viewing_documentViewer.View.PreferredItemType = DocumentViewerItemType.Svg;// Load a documentvar fileName = @"C:\LEADTOOLS22\Resources\Images\Leadtools.pdf";var document = DocumentFactory.LoadFromFile(fileName,new LoadDocumentOptions { UseCache = DocumentFactory.Cache != null });_documentViewer.Operation += (sender, e) =>{if (e.Operation == DocumentViewerOperation.LoadingBookmarks){// Disable the bookmarks when we are loading, enable when we are donevar rightPanel = this.Controls.Find("rightPanel", true)[0];if (rightPanel.InvokeRequired){rightPanel.Invoke((MethodInvoker)delegate { rightPanel.Enabled = e.IsPostOperation; });}else{rightPanel.Enabled = e.IsPostOperation;}}};// If we have an OCR engine, use itdocument.Text.OcrEngine = _ocrEngine;// Set it in the viewer_documentViewer.SetDocument(document);// Run pan/zoomvar interactiveComboBox = this.Controls.Find("interactiveComboBox", true)[0] as ComboBox;interactiveComboBox.SelectedItem = DocumentViewerCommands.InteractivePanZoom;}private void InitUI(){// Add a panel on the left for the document viewer thumbnails partvar leftPanel = new Panel();leftPanel.Name = "leftPanel";leftPanel.Width = 200;leftPanel.Dock = DockStyle.Left;leftPanel.BackColor = Color.Gray;leftPanel.BorderStyle = BorderStyle.FixedSingle;this.Controls.Add(leftPanel);// Add a panel to the right, this will work for the bookmarks or annotations partvar rightPanel = new Panel();rightPanel.Name = "rightPanel";rightPanel.Width = 200;rightPanel.Dock = DockStyle.Right;rightPanel.BackColor = Color.LightBlue;rightPanel.BorderStyle = BorderStyle.FixedSingle;this.Controls.Add(rightPanel);// Add a panel to fill the rest, for the document viewervar middlePanel = new Panel();middlePanel.Name = "middlePanel";middlePanel.BackColor = Color.DarkGray;middlePanel.BorderStyle = BorderStyle.None;middlePanel.Dock = DockStyle.Fill;this.Controls.Add(middlePanel);// Add a top panel to host our application controlsvar topPanel = new Panel();topPanel.Name = "topPanel";topPanel.Height = 100;topPanel.Dock = DockStyle.Top;topPanel.BorderStyle = BorderStyle.FixedSingle;this.Controls.Add(topPanel);middlePanel.BringToFront();// Add buttons for the UI// Combo box for interactive modesvar interactiveComboBox = new ComboBox();interactiveComboBox.Name = "interactiveComboBox";interactiveComboBox.DropDownStyle = ComboBoxStyle.DropDownList;// The command names for the items so we can just run theminteractiveComboBox.Items.Add(DocumentViewerCommands.InteractivePanZoom);interactiveComboBox.Items.Add(DocumentViewerCommands.InteractiveSelectText);interactiveComboBox.SelectedIndexChanged += (sender, e) =>{var commandName = interactiveComboBox.SelectedItem as string;_documentViewer.Commands.Run(commandName);};topPanel.Controls.Add(interactiveComboBox);// Generic label for information used by the examplesvar infoLabel = new Label();infoLabel.Name = "infoLabel";infoLabel.Text = "Info...";infoLabel.AutoSize = false;infoLabel.Width = 400;infoLabel.Left = interactiveComboBox.Right + 20;topPanel.Controls.Add(infoLabel);var exampleButton = new Button();exampleButton.Top = interactiveComboBox.Bottom + 2;exampleButton.Name = "exampleButton";exampleButton.Text = "&Example";exampleButton.Click += (sender, e) => Example(exampleButton);topPanel.Controls.Add(exampleButton);}private void Example(Button exampleButton){// Add the example code hereConsole.WriteLine(this + " Ready");}}