SelectPdf for .NET 10 - Pdf Redaction - C# / .NET 10 Sample

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.AspNetCore.Mvc.Rendering;
using SelectPdf.Universal;

namespace SelectPdf.Samples.Pages
{
    public class PdfRedactionModel : PageModel
    {
        public void OnGet()
        {
            TxtText = "SelectPdf";
            ChkWholeWords = true;
            DdlFillColor = "Black";
            TxtAreaPage = "1";
        }

        // An uploaded PDF document, or nothing - the shipped files/selectpdf.pdf is redacted then.
        [BindProperty]
        public IFormFile FilePdf { get; set; }

        [BindProperty]
        public string TxtText { get; set; }

        [BindProperty]
        public bool ChkCaseSensitive { get; set; }

        [BindProperty]
        public bool ChkWholeWords { get; set; }

        [BindProperty]
        public string TxtPattern { get; set; }

        [BindProperty]
        public string TxtOverlay { get; set; }

        [BindProperty]
        public string TxtPassword { get; set; }

        [BindProperty]
        public string DdlFillColor { get; set; }

        public List<SelectListItem> FillColors { get; } = new List<SelectListItem>
        {
            new SelectListItem { Value = "Black", Text = "Black" },
            new SelectListItem { Value = "Gray", Text = "Gray" },
            new SelectListItem { Value = "White", Text = "White" },
        };

        [BindProperty]
        public string TxtAreaPage { get; set; }

        [BindProperty]
        public string TxtAreaX { get; set; }

        [BindProperty]
        public string TxtAreaY { get; set; }

        [BindProperty]
        public string TxtAreaWidth { get; set; }

        [BindProperty]
        public string TxtAreaHeight { get; set; }

        public IActionResult OnPost()
        {
            // the document to redact: the uploaded one, or the test file
            byte[] source;
            if (FilePdf != null && FilePdf.Length > 0)
            {
                using (var uploaded = new MemoryStream())
                {
                    FilePdf.CopyTo(uploaded);
                    source = uploaded.ToArray();
                }
            }
            else
            {
                source = System.IO.File.ReadAllBytes(Path.Combine(Startup.ServerPath, "wwwroot", "files", "selectpdf.pdf"));
            }

            // load the document
            PdfRedactionManager manager = new PdfRedactionManager();
            if (string.IsNullOrEmpty(TxtPassword))
                manager.Load(source);
            else
                manager.Load(source, TxtPassword);

            // the color that covers the redacted areas
            switch (DdlFillColor)
            {
                case "Gray":
                    manager.FillColor = new PdfColor(128, 128, 128);
                    break;
                case "White":
                    manager.FillColor = new PdfColor(255, 255, 255);
                    break;
                default:
                    manager.FillColor = new PdfColor(0, 0, 0);
                    break;
            }

            // a text written in each redacted area
            if (!string.IsNullOrEmpty(TxtOverlay))
            {
                manager.OverlayText = TxtOverlay;
                // white on black and gray, black on white
                manager.OverlayTextColor = DdlFillColor == "White" ? new PdfColor(0, 0, 0) : new PdfColor(255, 255, 255);
            }

            // every occurrence of a text
            if (!string.IsNullOrEmpty(TxtText))
            {
                manager.AddRedaction(TxtText, ChkCaseSensitive, ChkWholeWords);
            }

            // every match of a regular expression
            if (!string.IsNullOrEmpty(TxtPattern))
            {
                manager.AddRedaction(new System.Text.RegularExpressions.Regex(TxtPattern,
                    ChkCaseSensitive ? System.Text.RegularExpressions.RegexOptions.None : System.Text.RegularExpressions.RegexOptions.IgnoreCase,
                    TimeSpan.FromSeconds(2)));
            }

            // a rectangle on a page
            if (TryNumber(TxtAreaWidth, out float width) && TryNumber(TxtAreaHeight, out float height)
                && width > 0 && height > 0)
            {
                TryNumber(TxtAreaX, out float x);
                TryNumber(TxtAreaY, out float y);
                int pageNumber = TryNumber(TxtAreaPage, out float page) ? (int)page : 1;
                manager.AddRedaction(pageNumber - 1, new SelectPdf.Universal.Drawing.RectangleF(x, y, width, height));
            }

            // apply the redaction and save the redacted document
            manager.Redact();
            byte[] pdf = manager.Save();

            // close the manager
            manager.Close();

            // return resulted pdf document
            FileResult fileResult = new FileContentResult(pdf, "application/pdf");
            fileResult.FileDownloadName = "Document.pdf";
            return fileResult;
        }

        private static bool TryNumber(string text, out float value)
        {
            return float.TryParse(text, NumberStyles.Float, CultureInfo.InvariantCulture, out value);
        }
    }
}