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public static IntPtr CreateLeadDC(RasterImage image)
image
The source image.
The Windows HDC object this method creates.
This method allows you to create an infinite number of drawing capabilities such as paint, erase, color erase and brush, pen, spray gun, flood fill, color tube, text overlay, curve, line, rectangle, polygon, ellipse, freehand shapes, cut and paste, and more.
All Windows GDI functions can be used to draw to the image using the returned HDC. The HDC must be freed with the DeleteLeadDC method.
If a region is defined for the image, GDI functions act only on the region, not on the entire image.
The DIB driver supports only 1, 4, 8, 16 and 24 bit images. If you are using an image that has some other number of bits per pixel, you must use Leadtools.ImageProcessing.ColorResolutionCommand to change the image to a bits per pixel value supported by the DIB driver.
For more information refer to RasterImage and GDI/GDI+ and Introduction to Image Processing With LEADTOOLS.
This example draws an ellipse on a raster image.
using Leadtools;using Leadtools.Codecs;using Leadtools.Drawing;using Leadtools.ImageProcessing;public void CreateLeadDCExample(){RasterCodecs codecs = new RasterCodecs();RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"));LeadPoint point1 = new LeadPoint(image.Width / 8, image.Height / 8);LeadPoint point2 = new LeadPoint(image.Width / 2, image.Height / 2);// Convert the coordinates if necessary.if (image.ViewPerspective != RasterViewPerspective.TopLeft){point1 = image.PointToImage(RasterViewPerspective.TopLeft, point1);point2 = image.PointToImage(RasterViewPerspective.TopLeft, point2);}// Create the device contextIntPtr hdc = RasterImagePainter.CreateLeadDC(image);using (Graphics g = Graphics.FromHdc(hdc)){g.DrawEllipse(new Pen(Color.White), point1.X, point1.Y, point2.X - point1.X, point2.Y - point1.Y);}RasterImagePainter.DeleteLeadDC(hdc);codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "Imahe1_CreateLeadDC.bmp"), RasterImageFormat.Bmp, 0);image.Dispose();codecs.Dispose();}static class LEAD_VARS{public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images";}