NotSourceErase Field

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Drawing; 
 
 
public void RasterPaintPropertiesExample() 
{ 
   // Create the form  
   PaintPropertiesForm f = new PaintPropertiesForm(); 
   f.ShowDialog(); 
} 
 
class PaintPropertiesForm : Form 
{ 
   private int index = 0; 
   private RasterImage rasterImage; 
   private RasterPaintProperties paintProperties; 
 
   public PaintPropertiesForm() 
   { 
      Text = "GDI paint engine - normal - Double click to show next RasterPaintProperties options"; 
      SetStyle(ControlStyles.ResizeRedraw, true); 
      SetStyle(ControlStyles.AllPaintingInWmPaint, true); 
      SetStyle(ControlStyles.OptimizedDoubleBuffer, true); 
      SetStyle(ControlStyles.UserPaint, true); 
 
      // Load an image  
      string fileName = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif"); 
 
      using (RasterCodecs codecs = new RasterCodecs()) 
      { 
         codecs.ThrowExceptionsOnInvalidImages = true; 
         rasterImage = codecs.Load(fileName); 
      } 
 
      paintProperties = RasterPaintProperties.Default; 
 
      // Start with GDI paint engine and normal paint scaling 
      paintProperties.PaintEngine = RasterPaintEngine.Gdi; 
      paintProperties.PaintDisplayMode = RasterPaintDisplayModeFlags.None; 
   } 
 
   protected override void Dispose(bool disposing) 
   { 
      if (disposing) 
      { 
         if (rasterImage != null) 
            rasterImage.Dispose(); 
      } 
 
      base.Dispose(disposing); 
   } 
 
   protected override void OnDoubleClick(EventArgs e) 
   { 
      switch (index) 
      { 
         case 0: 
            Text = "GDI paint engine - SourceAnd ROP - Double click to show next RasterPaintProperties options"; 
            paintProperties.RasterOperation = RasterPaintProperties.SourceAnd; 
            break; 
 
         case 1: 
            Text = "GDI paint engine - Scale to gray - Double click to show next RasterPaintProperties options"; 
            paintProperties.RasterOperation = RasterPaintProperties.SourceCopy; 
            paintProperties.PaintDisplayMode = RasterPaintDisplayModeFlags.ScaleToGray; 
            break; 
 
         case 2: 
            Text = "GDI+ paint engine - Double click to set the opacity"; 
            paintProperties.PaintEngine = RasterPaintEngine.GdiPlus; 
            break; 
 
         case 3: 
            Text = "GDI+ paint engine - Opacity set to 50% - Done"; 
            paintProperties.Opacity = 128; 
            break; 
 
         default: 
            break; 
      } 
 
      index++; 
      Invalidate(); 
      base.OnDoubleClick(e); 
   } 
 
   protected override void OnPaint(PaintEventArgs e) 
   { 
      // Paint the image  
      LeadRect destRect = LeadRect.FromLTRB(ClientRectangle.Left, ClientRectangle.Top, ClientRectangle.Right, ClientRectangle.Bottom); 
      destRect = RasterImage.CalculatePaintModeRectangle( 
         rasterImage.ImageWidth, 
         rasterImage.ImageHeight, 
         destRect, 
         RasterPaintSizeMode.Fit, 
         RasterPaintAlignMode.Center, 
         RasterPaintAlignMode.Center); 
 
      RasterImagePainter.Paint(rasterImage, e.Graphics, destRect, paintProperties); 
 
      base.OnPaint(e); 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}