public enum RasterPaintEngine
Value | Member | Description |
---|---|---|
0 | Gdi | Use Windows GDI when painting Leadtools.RasterImage objects |
1 | GdiPlus | Use Windows GDI+ when painting Leadtools.RasterImage objects |
When the RasterPaintEngine.Gdi engine is used, the RasterImagePainter.Paint method internally will call the Win32 API functions to paint the image.
When the RasterPaintEngine.GdiPlus engine is used, the RasterImagePainter.Paint method internally will call GDI+ Graphics.DrawImage methods to paint the image. Note that if the Leadtools.RasterImage object is not fully compatible with GDI+, the framework will internally make a copy of parts of the image data (bands) and paints them to the destination device. The original data is not converted and no changes will be made to the original image.
Choosing a paint engine depends on the Leadtools.RasterImage object and your specific needs:
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";
}