RenderRedirect Method

using Leadtools; 
using Leadtools.Controls; 
using Leadtools.Codecs; 
using Leadtools.Drawing; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
 
 
public ImageViewerForm _form = new ImageViewerForm(); 
public ImageViewer _imageViewer; 
public PictureBox redirectRenderControl; 
 
public void ImageViewerRedirectRenderExample() 
{ 
   // Get the ImageViewer control from the form 
   _imageViewer = _form.ImageViewer; 
 
   // Load an image 
   using (var codecs = new RasterCodecs()) 
      _imageViewer.Image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "cannon.jpg")); 
 
   // PanZoom Interactive Mode 
   _imageViewer.DefaultInteractiveMode = new ImageViewerPanZoomInteractiveMode(); 
 
   // Separate Form with PictureBox control 
   Form redirectRenderForm = new Form(); 
   redirectRenderControl = new PictureBox(); 
   redirectRenderControl.Width = 400; 
   redirectRenderControl.Dock = DockStyle.Fill; 
   redirectRenderForm.Controls.Add(redirectRenderControl); 
   redirectRenderForm.Show(); 
 
   // Invalidate on double-click 
   bool renderView = false; 
   redirectRenderControl.DoubleClick += (sender, e) => 
   { 
      renderView = !renderView; 
      redirectRenderControl.Invalidate(); 
   }; 
 
             
   redirectRenderControl.Paint += (sender, e) => 
   { 
      if (_imageViewer.Image == null) 
         return; 
 
      // Get PictureBox Graphics object 
      Graphics graphics = e.Graphics; 
 
      // Destination rectangle in PictureBox 
      int margin = 20; 
      LeadRect destRect = LeadRect.Create(margin, margin, redirectRenderControl.ClientSize.Width - margin * 2, redirectRenderControl.ClientSize.Height - margin * 2); 
      LeadRect clipRect = destRect; 
 
      // Source rectangle 
      Debug.WriteLine(_imageViewer.ViewSize); 
 
      // RenderRedirect Options 
      ImageViewerRenderRedirectOptions options = new ImageViewerRenderRedirectOptions(); 
      options.BackgroundColor = Color.Transparent; 
 
      // Try to get item from the viewer 
      ImageViewerItem item = null; 
      if (!renderView) 
         item = _imageViewer.Items[0]; 
      LeadRectD sourceRect = LeadRectD.Empty; 
 
      if (item == null) 
         sourceRect = _imageViewer.GetViewBounds(true, false); 
      else 
      { 
         sourceRect = _imageViewer.GetItemViewBounds(item, ImageViewerItemPart.Image, false); 
         options.RenderBackgrounds = false; 
         options.RenderBorders = false; 
         options.RenderItemStates = false; 
         options.RenderShadows = false; 
         options.RenderText = false; 
      } 
 
      // Transformation Matrix (represents rotation, zooming...etc)  
      Debug.WriteLine(_imageViewer.ViewTransform); 
      options.CreateTransform(_imageViewer, destRect, sourceRect, ControlSizeMode.FitAlways, ControlAlignment.Center, ControlAlignment.Center); 
      clipRect = options.Transform.TransformRect(sourceRect).ToLeadRect(); 
 
      // Redirect rendering to the PictureBox Graphics object (Outlined with a black rectangle) 
      _imageViewer.RenderRedirect(graphics, options, clipRect); 
      graphics.DrawRectangle(Pens.Black, destRect.X, destRect.Y, destRect.Width + 1, destRect.Height + 1); 
 
      // Calculate visible view 
      LeadRectD rect; 
      if (item == null) 
         rect = _imageViewer.GetViewBounds(true, true); 
      else 
         rect = _imageViewer.GetItemViewBounds(item, ImageViewerItemPart.Image, true); 
 
      LeadPointD[] points = 
      { 
            LeadPointD.Create(rect.Left, rect.Top), 
            LeadPointD.Create(rect.Right, rect.Bottom) 
      }; 
 
      options.Transform.TransformPoints(points); 
 
      double xmin = points[0].X; 
      double ymin = points[0].Y; 
      double xmax = xmin; 
      double ymax = ymin; 
 
      for (int i = 1; i < points.Length; i++) 
      { 
         if (points[i].X < xmin) xmin = points[i].X; 
         if (points[i].X > xmax) xmax = points[i].X; 
         if (points[i].Y < ymin) ymin = points[i].Y; 
         if (points[i].Y > ymax) ymax = points[i].Y; 
      } 
 
      // Draw yellow rectangle showing visible part of the view 
      LeadRectD bounds = LeadRectD.FromLTRB(xmin, ymin, xmax, ymax); 
      RectangleF rc = new RectangleF((float)bounds.X, (float)bounds.Y, (float)bounds.Width, (float)bounds.Height); 
      graphics.DrawRectangle(Pens.Yellow, rc.X, rc.Y, rc.Width - 1, rc.Height - 1); 
   }; 
 
   _imageViewer.RedirectRender += (sender, e) => 
   { 
      redirectRenderControl.Invalidate(); 
   }; 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}