// 完毕:
using System;
using System.IO;
using System.Drawing;
using GrapeCity.Documents.Pdf;
using GrapeCity.Documents.Text;
using GrapeCity.Documents.Drawing;
using GCTEXT = GrapeCity.Documents.Text;
using GCDRAW = GrapeCity.Documents.Drawing;
namespace DsPdfWeb.Demos
{
// Using image alignment options in DsPdf.
// (This example replaces the older RawImages example; the RawImage class is obsolete and should not be used.)
//
// NOTE: When you render an image in DsPdf multiple times (e.g. rendering
// the same image as part of a page header on all pages), it will automatically be
// added to a dictionary and reused throughout the document, provided you use
// the same image object on all pages. So rather than loading the same image from
// file (or stream) each time it is needed, it is always preferable to load the image
// once and cache it in an image object. This applies to all image types used in DsPdf.
public class ImageAlignment
{
public int CreatePDF(Stream stream)
{
var doc = new GcPdfDocument();
// Text format used to draw captions:
var tf = new TextFormat() { Font = StandardFonts.Times, FontSize = 12 };
// Action to draw the image with various alignment options:
Action<GCDRAW.Image, Page, ImageAlign, bool> drawImage = (image_, page_, ia_, clip_) =>
{
var rect = new RectangleF(72, 72, 72 * 4, 72 * 4);
var clipped = clip_ ? "clipped to a 4\"x4\" rectangle" : "without clipping";
var align = ia_ == ImageAlign.Default ? "ImageAlign.Default" :
ia_ == ImageAlign.CenterImage ? "ImageAlign.CenterImage" :
ia_ == ImageAlign.StretchImage ? "ImageAlign.StretchImage" : "custom ImageAlign";
// Draw image caption:
page_.Graphics.DrawString($"Page {doc.Pages.IndexOf(page_) + 1}: Image drawn at (1\",1\"), {clipped}, using {align}:", tf, new PointF(72, 36));
var clip = clip_ ? new Nullable<RectangleF>(rect) : new Nullable<RectangleF>();
// Draw the image:
page_.Graphics.DrawImage(image_, rect, clip, ia_, out RectangleF[] imageRects);
// Show the image outline:
page_.Graphics.DrawRectangle(imageRects[0], Color.Red, 1, null);
// Show image/clip area:
page_.Graphics.DrawRectangle(rect, Color.Blue, 1, null);
};
// Create images from JPEG files (using the same Image class instance to draw an image
// in a PDF ensures that the image data will be reused and not duplicated in the PDF):
using var image = GCDRAW.Image.FromFile(Path.Combine("Resources", "Images", "puffins.jpg"));
using var imageSmall = GCDRAW.Image.FromFile(Path.Combine("Resources", "ImagesBis", "puffins-small.jpg"));
// The ImageAlign class provides various image alignment options.
// It also defines a few static instances with some commonly used
// combinations of options demonstrated below.
// Page 1: draw image without clipping, with default alignment:
drawImage(image, doc.NewPage(), ImageAlign.Default, false);
// Page 2: draw image with clipping, with default alignment:
drawImage(image, doc.NewPage(), ImageAlign.Default, true);
// Page 3: draw image with clipping, with CenterImage alignment:
drawImage(image, doc.NewPage(), ImageAlign.CenterImage, true);
// Page 4: draw image without clipping and stretched image:
drawImage(image, doc.NewPage(), ImageAlign.StretchImage, false);
// Page 5: draw image without clipping, fit into the rectangle, preserving aspect ratio:
var ia = new ImageAlign(ImageAlignHorz.Center, ImageAlignVert.Center, true, true, true, false, false);
drawImage(image, doc.NewPage(), ia, false);
// Page 6: draw a small image tiled, without clipping, fit into the rectangle, preserving aspect ratio:
ia = new ImageAlign(ImageAlignHorz.Left, ImageAlignVert.Top, false, false, true, true, true);
drawImage(imageSmall, doc.NewPage(), ia, false);
// 完毕:
doc.Save(stream);
return doc.Pages.Count;
}
}
}