RasterThumbnailBrowser Class

using Leadtools.WinForms;
using Leadtools;
using Leadtools.Codecs;
using Leadtools.Drawing;

class MyForm : Form
{
   public RasterThumbnailBrowser theBrowser;
   public bool cancelOperation;        // Informs us if the user canceled the operation
   public Button buttonCancel;         // Cancel browse loading
   public Button buttonBrowse;         // Diplays the browse control
   public ProgressBar progressBar;     // shows progress of loading browse images
   void buttonBrowse_Click(object sender, EventArgs e)
   {
      // If we are already loading thumbails, cancel
      // this operation
      if(theBrowser.IsLoadingThumbnails)
         theBrowser.CancelLoadingThumbnails();

      // Clean all the items
      theBrowser.Items.Clear();

      // Update the application state
      buttonCancel.Enabled = true;
      progressBar.Value = 0;

      // And load the new thumbnails
      cancelOperation = false;

      string folderPath = LEAD_VARS.ImagesDir;
      theBrowser.LoadThumbnails(folderPath, "*.*", RasterThumbnailBrowserLoadFlags.Block);

      theBrowser.Refresh();

      theBrowser.EnableBroswerWatcher = true;
   }

   private void thumbnailBrowser_LoadThumbnail(object sender, RasterThumbnailBrowserLoadThumbnailEventArgs e)
   {
      // If this is the first iteration, update the progress bar minimum and maximum values
      if(e.Index == 0)
      {
         progressBar.Minimum = 0;
         progressBar.Maximum = e.Total - 1;
      }

      // Update where we are in the loading operation
      progressBar.Value = e.Index;

      // Check if we need to cancel (due to the user clicking the Cancel button)
      if(cancelOperation)
         e.Cancel = true;
   }

   private void thumbnailBrowser_AddFile(object sender, RasterThumbnailBrowserAddFileEventArgs e)
   {
      Console.WriteLine("AddFile: {0}    Add: {1}", e.FileName, e.Add);
   }

   private void thumbnailBrowser_FinishedLoadingThumbnails(object sender, EventArgs e)
   {
      buttonCancel.Enabled = false;
   }

   private void buttonCancel_Click(object sender, EventArgs e)
   {
      // The user has clicked the cancel button
      this.cancelOperation = true;
   }

   // Create  custom images to use as the "error" and "loading" thumbnails.
   void CreateErrorThumbnail()
   {
      // Get the image size
      Size imageSize = theBrowser.ItemImageSize;

      // No "loading" thumbnail
      theBrowser.LoadingThumbnail = null;

      // For the "error" thumbnail, create a red X image
      RasterColor[] palette = new RasterColor[0];
      RasterImage image = new RasterImage(
         RasterMemoryFlags.Conventional,
         imageSize.Width,
         imageSize.Height,
         24,
         RasterByteOrder.Bgr,
         RasterViewPerspective.TopLeft,
      palette,
      IntPtr.Zero,
      0
      );

      IntPtr hdc = RasterImagePainter.CreateLeadDC(image);
      Graphics g = Graphics.FromHdc(hdc);

      g.FillRectangle(Brushes.Magenta, 0, 0, imageSize.Width, imageSize.Height);

      g.DrawLine(Pens.Red, 0, 0, imageSize.Width, imageSize.Height);
      g.DrawLine(Pens.Red, imageSize.Width, 0, 0, imageSize.Height);

      g.Dispose();
      RasterImagePainter.DeleteLeadDC(hdc);

      // Make this image transparent
      image.Transparent = true;
      image.TransparentColor = RasterColor.FromKnownColor(RasterKnownColor.Magenta);

      theBrowser.ErrorThumbnail = image;
   }

   public void Cleanup()
   {
      buttonBrowse.Click -= new EventHandler(buttonBrowse_Click);
      buttonCancel.Click -= new EventHandler(buttonCancel_Click);
      theBrowser.LoadThumbnail -= new EventHandler<RasterThumbnailBrowserLoadThumbnailEventArgs>(thumbnailBrowser_LoadThumbnail);
      theBrowser.FinishedLoadingThumbnails -= new EventHandler(thumbnailBrowser_FinishedLoadingThumbnails);
   }

   public MyForm()
   {
      Size = new Size(300, 200);

      // create the browser
      theBrowser = new RasterThumbnailBrowser();
      theBrowser.Codecs = new RasterCodecs();
      theBrowser.Dock = DockStyle.Fill;
      theBrowser.ItemSpacingSize = new Size(10, 10);
      theBrowser.ThumbnailSizeFlags = RasterSizeFlags.Bicubic;
      theBrowser.LoadThumbnail += new EventHandler<RasterThumbnailBrowserLoadThumbnailEventArgs>(thumbnailBrowser_LoadThumbnail);
      theBrowser.FinishedLoadingThumbnails += new EventHandler(thumbnailBrowser_FinishedLoadingThumbnails);
      theBrowser.AddFile += new EventHandler<RasterThumbnailBrowserAddFileEventArgs>(thumbnailBrowser_AddFile);

      // Create a thumbnail image to be displayed on error
      CreateErrorThumbnail();

      // add a panel
      Panel panel = new Panel();
      panel.Dock = DockStyle.Left;
      panel.Width = 100;
      Controls.Add(panel);
      panel.BringToFront();

      // add a "browse" button
      buttonBrowse = new Button();
      buttonBrowse.Text = "Browse";
      buttonBrowse.Dock = DockStyle.Top;
      panel.Controls.Add(buttonBrowse);
      buttonBrowse.Click += new EventHandler(buttonBrowse_Click);

      // add a "cancel" button
      buttonCancel = new Button();
      buttonCancel.Text = "Cancel";
      buttonBrowse.Dock = DockStyle.Bottom;
      panel.Controls.Add(buttonCancel);
      buttonCancel.Click += new EventHandler(buttonCancel_Click);

      // add a progress bar
      progressBar = new ProgressBar();
      progressBar.Dock = DockStyle.Bottom;
      Controls.Add(progressBar);

      Controls.Add(theBrowser);
      theBrowser.BringToFront();
   }

   private void InitializeComponent()
   {
      this.SuspendLayout();
      // 
      // MyForm
      // 
      this.ClientSize = new System.Drawing.Size(315, 273);
      this.Name = "MyForm";
      this.ResumeLayout(false);

   }
} 
public void RasterThumbnailBrowser_RasterThumbnailBrowser()
{
   MyForm form = new MyForm();
   form.ShowDialog();
   form.Cleanup();
}

static class LEAD_VARS
{
public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}