NoPassGetPageInfo.cs
// 完毕:
using System;
using System.IO;
using System.Drawing;
using GrapeCity.Documents.Pdf;
using GrapeCity.Documents.Text;

namespace DsPdfWeb.Demos
{
    // This example shows how to load a password protected PDF and get its page count and page sizes.
    // For reference, the loaded PDF is protected with the owner password 'owner' and user password 'user'.
    public class NoPassGetPageInfo
    {
        public int CreatePDF(Stream stream)
        {
            using var fs = File.OpenRead(Path.Combine("Resources", "PDFs", "Wetlands-password-user.pdf"));
            // Set up DecryptionOptions to allow loading password protected PDFs without password:
            var dopt = new DecryptionOptions() { ThrowExceptionIfInvalidPassword = false };
            var docSrc = new GcPdfDocument();
            docSrc.Load(fs, dopt);

            // The PDF to hold the results:
            var doc = new GcPdfDocument();
            var page = doc.NewPage();
            // Set up a TextLayout to format the results:
            var tl = page.Graphics.CreateTextLayout();
            tl.DefaultFormat.Font = StandardFonts.Courier;
            tl.DefaultFormat.FontSize = 14;
            tl.MaxWidth = doc.PageSize.Width;
            tl.MaxHeight = doc.PageSize.Height;
            tl.MarginAll = tl.Resolution;
            var captionFmt = new TextFormat(tl.DefaultFormat) { Font = StandardFonts.CourierBold };

            // Get and print some of the source PDF stats:
            tl.AppendLine($"The source PDF contains {docSrc.Pages.Count} page(s).", captionFmt);
            foreach (var pg in  docSrc.Pages)
            {
                tl.AppendLine($"  Page at index {pg.Index}:", captionFmt);
                var sz = pg.GetRenderSize();
                tl.AppendLine($"    Page size is {sz.Width}x{sz.Height}.");
                tl.AppendLine($"    Page has {(pg.Landscape ? "landscape" : "portrait")} orientation.");
                tl.AppendLine($"    Page paper kind is '{pg.PaperKind}'.");
            }

            // Render the results:
            tl.PerformLayout(true);
            while (true)
            {
                var splitResult = tl.Split(null, out TextLayout rest);
                page.Graphics.DrawTextLayout(tl, PointF.Empty);
                if (splitResult != SplitResult.Split)
                    break;
                tl = rest;
                tl.MarginTop = tl.Resolution;
                page = doc.Pages.Add();
            }

            // 完毕:
            doc.Save(stream);
            return doc.Pages.Count;
        }
    }
}