TimeSheetIncremental.cs
// 完毕:
using System;
using System.IO;
using System.Linq;
using System.Drawing;
using System.Collections.Generic;
using GrapeCity.Documents.Pdf;
using GrapeCity.Documents.Pdf.AcroForms;
using GrapeCity.Documents.Text;
using GrapeCity.Documents.Common;
using GrapeCity.Documents.Drawing;
using GrapeCity.Documents.Pdf.Security;
using System.Security.Cryptography.X509Certificates;
using GCTEXT = GrapeCity.Documents.Text;
using GCDRAW = GrapeCity.Documents.Drawing;

namespace DsPdfWeb.Demos
{
    // 这个示例与TimeSheet几乎相同,但有一个显着差异:
    // 与其他示例不同,在此示例中,填写的表格由以下人员进行数字签名
    // 员工,并且主管使用签名的 PDF 再次签名
    // 增量更新(在已签名的 PDF 上签名的唯一方法
    // 保留第一个签名的有效性)。
    // 
    // 注意:如果您下载此示例并在您自己的系统上本地运行它,
    // 您需要拥有有效的许可证才能使其按预期工作,因为
    // 在未经许可的版本中,自动添加的导航页面标题将
    // 使员工签名无效。
    public class TimeSheetIncremental
    {
        // 字体集合来保存我们需要的字体:
        private FontCollection _fc = new FontCollection();
        // 展平文档时用于呈现输入字段的文本布局:
        private TextLayout _inputTl = new TextLayout(72);
        // 用于输入字段的文本格式:
        private TextFormat _inputTf = new TextFormat();
        private GCTEXT.Font _inputFont = FontCollection.SystemFonts.FindFamilyName("Segoe UI", true);
        private float _inputFontSize = 12;
        // 输入字段边距:
        private float _inputMargin = 5;
        // 员工签名空间:
        private RectangleF _empSignRect;
        //
        private GCDRAW.Image _logo;

        // 该示例的主要入口点:
        public int CreatePDF(Stream stream)
        {
            // 使用我们需要的字体设置字体集合:
            _fc.RegisterDirectory(Path.Combine("Resources", "Fonts"));
            // 在输入字段的文本布局上设置该字体集合
            // (我们还将在我们将使用的所有文本布局上设置它):
            _inputTl.FontCollection = _fc;
            // 设置输入字段的布局和格式:
            _inputTl.ParagraphAlignment = ParagraphAlignment.Center;
            _inputTf.Font = _inputFont;
            _inputTf.FontSize = _inputFontSize;

            // 创建时间表输入表单
            // (在现实生活中,我们可能只会创建一次,
            // 然后重新使用 PDF 表单):
            var doc = MakeTimeSheetForm();

            // 此时,“doc”是一个空的 AcroForm。
            // 在现实生活中的应用程序中,它将分发给员工
            // 让他们填写并寄回。
            using (var empSignedStream = FillEmployeeData(doc))
            {
                // 此时,“empSignedStream”包含填写了员工数据并由他们签名的表单。

                // 加载员工签名的文档:
                doc.Load(empSignedStream);

                // 填写主管数据:
                var supName = "Jane Donahue";
                var supSignDate = Common.Util.TimeNow().ToShortDateString();
                SetFieldValue(doc, _Names.EmpSuper, supName);
                SetFieldValue(doc, _Names.SupSignDate, supSignDate);

                // 代表主管对文档进行数字签名:
                var pfxPath = Path.Combine("Resources", "Misc", "DsPdfTest.pfx");
                var cert = new X509Certificate2(File.ReadAllBytes(pfxPath), "qq",
                    X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.PersistKeySet | X509KeyStorageFlags.Exportable);
                var sp = new SignatureProperties()
                {
                    SignatureBuilder = new Pkcs7SignatureBuilder()
                    {
                        CertificateChain = new X509Certificate2[] { cert },
                        HashAlgorithm = OID.HashAlgorithms.SHA512
                    },
                    Location = "DsPdfWeb - TimeSheet Incremental",
                    SignerName = supName,
                    SigningDateTime = Common.Util.TimeNow(),
                    // 连接签名字段和签名属性:
                    SignatureField = doc.AcroForm.Fields.First(f_ => f_.Name == _Names.SupSign) as SignatureField,
                };

                // 对文档的任何更改都会使员工的签名无效,因此我们不能这样做:
                // supSign.Widget.ButtonAppearance.Caption =supName;
                // 
                // 完成后,现在保存带有主管签名的文档:
                // 注意:为了不使员工的签名无效,
                // 我们必须在这里使用增量更新(在 Sign() 方法中默认是这样):
                doc.Sign(sp, stream);
                _logo.Dispose();
                return doc.Pages.Count;
            }
        }

        // 将文档中的任何文本字段替换为常规文本,
        // 除了“excludeFields”中列出的字段:
        private void FlattenDoc(GcPdfDocument doc, params string[] excludeFields)
        {
            foreach (var f in doc.AcroForm.Fields)
            {
                if (f is TextField fld && !excludeFields.Contains(fld.Name))
                {
                    var w = fld.Widget;
                    var g = w.Page.Graphics;
                    _inputTl.Clear();
                    _inputTl.Append(fld.Value, _inputTf);
                    _inputTl.MaxHeight = w.Rect.Height;
                    _inputTl.PerformLayout(true);
                    g.DrawTextLayout(_inputTl, w.Rect.Location);
                }
            }
            for (int i = doc.AcroForm.Fields.Count - 1; i >= 0; --i)
                if (doc.AcroForm.Fields[i] is TextField fld && !excludeFields.Contains(fld.Name))
                    doc.AcroForm.Fields.RemoveAt(i);
        }

        // 数据字段名称:
        static class _Names
        {
            public static readonly string[] Dows = new string[]
            {
                "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
            };
            public const string EmpName = "empName";
            public const string EmpTitle = "empTitle";
            public const string EmpNum = "empNum";
            public const string EmpStatus = "empStatus";
            public const string EmpDep = "empDep";
            public const string EmpSuper = "empSuper";
            public static Dictionary<string, string[]> DtNames = new Dictionary<string, string[]>()
            {
                {"Sun", new string[] { "dtSun", "tSunStart", "tSunEnd", "tSunReg", "tSunOvr", "tSunTotal" } },
                {"Mon", new string[] { "dtMon", "tMonStart", "tMonEnd", "tMonReg", "tMonOvr", "tMonTotal" } },
                {"Tue", new string[] { "dtTue", "tTueStart", "tTueEnd", "tTueReg", "tTueOvr", "tTueTotal" } },
                {"Wed", new string[] { "dtWed", "tWedStart", "tWedEnd", "tWedReg", "tWedOvr", "tWedTotal" } },
                {"Thu", new string[] { "dtThu", "tThuStart", "tThuEnd", "tThuReg", "tThuOvr", "tThuTotal" } },
                {"Fri", new string[] { "dtFri", "tFriStart", "tFriEnd", "tFriReg", "tFriOvr", "tFriTotal" } },
                {"Sat", new string[] { "dtSat", "tSatStart", "tSatEnd", "tSatReg", "tSatOvr", "tSatTotal" } },
            };
            public const string TotalReg = "totReg";
            public const string TotalOvr = "totOvr";
            public const string TotalHours = "totHours";
            public const string EmpSign = "empSign";
            public const string EmpSignDate = "empSignDate";
            public const string SupSign = "supSign";
            public const string SupSignDate = "supSignDate";
        }

        // 创建考勤表表单:
        private GcPdfDocument MakeTimeSheetForm()
        {
            const float marginH = 72, marginV = 48;
            var doc = new GcPdfDocument();
            var page = doc.NewPage();
            var g = page.Graphics;
            var ip = new PointF(marginH, marginV);

            var tl = new TextLayout(g.Resolution) { FontCollection = _fc };

            tl.Append("TIME SHEET", new TextFormat() { FontName = "Segoe UI", FontSize = 18 });
            tl.PerformLayout(true);
            g.DrawTextLayout(tl, ip);
            ip.Y += tl.ContentHeight + 15;

            _logo = GCDRAW.Image.FromFile(Path.Combine("Resources", "ImagesBis", "AcmeLogo-vertical-250px.png"));
            var s = new SizeF(250f * 0.75f, 64f * 0.75f);
            g.DrawImage(_logo, new RectangleF(ip, s), null, ImageAlign.Default);
            ip.Y += s.Height + 5;

            tl.Clear();
            tl.Append("Where Business meets Technology",
                new TextFormat() { FontName = "Segoe UI", FontItalic = true, FontSize = 10 });
            tl.PerformLayout(true);
            g.DrawTextLayout(tl, ip);
            ip.Y += tl.ContentHeight + 15;

            tl.Clear();
            tl.Append("1901, Halford Avenue,\r\nSanta Clara, California – 95051-2553,\r\nUnited States",
                new TextFormat() { FontName = "Segoe UI", FontSize = 9 });
            tl.MaxWidth = page.Size.Width - marginH * 2;
            tl.TextAlignment = TextAlignment.Trailing;
            tl.PerformLayout(true);
            g.DrawTextLayout(tl, ip);
            ip.Y += tl.ContentHeight + 25;

            var pen = new GCDRAW.Pen(Color.Gray, 0.5f);

            var colw = (page.Size.Width - marginH * 2) / 2;
            var fields1 = DrawTable(ip,
                new float[] { colw, colw },
                new float[] { 30, 30, 30 },
                g, pen);

            var tf = new TextFormat() { FontName = "Segoe UI", FontSize = 9 };
            tl.ParagraphAlignment = ParagraphAlignment.Center;
            tl.TextAlignment = TextAlignment.Leading;
            tl.MarginLeft = tl.MarginRight = tl.MarginTop = tl.MarginBottom = 4;

            // t_ - 标题
            // b_ - 边界
            // f_ - 字段名称,null表示没有字段
            Action<string, RectangleF, string> drawField = (t_, b_, f_) =>
            {
                float tWidth;
                if (!string.IsNullOrEmpty(t_))
                {
                    tl.Clear();
                    tl.MaxHeight = b_.Height;
                    tl.MaxWidth = b_.Width;
                    tl.Append(t_, tf);
                    tl.PerformLayout(true);
                    g.DrawTextLayout(tl, b_.Location);
                    tWidth = tl.ContentRectangle.Right;
                }
                else
                    tWidth = 0;
                if (!string.IsNullOrEmpty(f_))
                {
                    var fld = new TextField() { Name = f_ };
                    fld.Widget.Page = page;
                    fld.Widget.Rect = new RectangleF(
                        b_.X + tWidth + _inputMargin, b_.Y + _inputMargin,
                        b_.Width - tWidth - _inputMargin * 2, b_.Height - _inputMargin * 2);
                    fld.Widget.DefaultAppearance.Font = _inputFont;
                    fld.Widget.DefaultAppearance.FontSize = _inputFontSize;
                    fld.Widget.Border.Color = Color.LightSlateGray;
                    fld.Widget.Border.Width = 0.5f;
                    doc.AcroForm.Fields.Add(fld);
                }
            };

            drawField("EMPLOYEE NAME: ", fields1[0, 0], _Names.EmpName);
            drawField("TITLE: ", fields1[1, 0], _Names.EmpTitle);
            drawField("EMPLOYEE NUMBER: ", fields1[0, 1], _Names.EmpNum);
            drawField("STATUS: ", fields1[1, 1], _Names.EmpStatus);
            drawField("DEPARTMENT: ", fields1[0, 2], _Names.EmpDep);
            drawField("SUPERVISOR: ", fields1[1, 2], _Names.EmpSuper);

            ip.Y = fields1[0, 2].Bottom;

            float col0 = 100;
            colw = (page.Size.Width - marginH * 2 - col0) / 5;
            float rowh = 25;
            var fields2 = DrawTable(ip,
                new float[] { col0, colw, colw, colw, colw, colw },
                new float[] { 50, rowh, rowh, rowh, rowh, rowh, rowh, rowh, rowh },
                g, pen);

            tl.ParagraphAlignment = ParagraphAlignment.Far;
            drawField("DATE", fields2[0, 0], null);
            drawField("START TIME", fields2[1, 0], null);
            drawField("END TIME", fields2[2, 0], null);
            drawField("REGULAR HOURS", fields2[3, 0], null);
            drawField("OVERTIME HOURS", fields2[4, 0], null);
            tf.FontBold = true;
            drawField("TOTAL HOURS", fields2[5, 0], null);
            tf.FontBold = false;
            tl.ParagraphAlignment = ParagraphAlignment.Center;
            tf.ForeColor = Color.Gray;
            for (int i = 0; i < 7; ++i)
                drawField(_Names.Dows[i], fields2[0, i + 1], _Names.DtNames[_Names.Dows[i]][0]);
            // 垂直对齐日期字段(补偿不同的 DOW 宽度):
            var dowFields = doc.AcroForm.Fields.TakeLast(7);
            var minW = dowFields.Min(f_ => ((TextField)f_).Widget.Rect.Width);
            dowFields.ToList().ForEach(f_ =>
            {
                var r_ = ((TextField)f_).Widget.Rect;
                r_.Offset(r_.Width - minW, 0);
                r_.Width = minW;
                ((TextField)f_).Widget.Rect = r_;
            });

            tf.ForeColor = Color.Black;
            for (int row = 1; row <= 7; ++row)
                for (int col = 1; col <= 5; ++col)
                    drawField(null, fields2[col, row], _Names.DtNames[_Names.Dows[row - 1]][col]);

            tf.FontBold = true;
            drawField("WEEKLY TOTALS", fields2[0, 8], null);
            tf.FontBold = false;

            drawField(null, fields2[3, 8], _Names.TotalReg);
            drawField(null, fields2[4, 8], _Names.TotalOvr);
            drawField(null, fields2[5, 8], _Names.TotalHours);

            ip.Y = fields2[0, 8].Bottom;

            col0 = 72 * 4;
            colw = page.Size.Width - marginH * 2 - col0;
            var fields3 = DrawTable(ip,
                new float[] { col0, colw },
                new float[] { rowh + 10, rowh, rowh },
                g, pen);

            drawField("EMPLOYEE SIGNATURE: ", fields3[0, 1], null);
            // 员工签名:
            var r = fields3[0, 1];
            _empSignRect = new RectangleF(r.X + r.Width / 2, r.Y, r.Width / 2 - _inputMargin * 2, r.Height);
            var sf = new SignatureField() { Name = _Names.EmpSign };
            sf.Widget.Rect = new RectangleF(r.X + r.Width / 2, r.Y + _inputMargin, r.Width / 2 - _inputMargin * 2, r.Height - _inputMargin * 2);
            sf.Widget.Page = page;
            sf.Widget.BackColor = Color.LightSeaGreen;
            doc.AcroForm.Fields.Add(sf);
            drawField("DATE: ", fields3[1, 1], _Names.EmpSignDate);

            drawField("SUPERVISOR SIGNATURE: ", fields3[0, 2], null);
            // 主管签字:
            r = fields3[0, 2];
            sf = new SignatureField() { Name = _Names.SupSign };
            sf.Widget.Rect = new RectangleF(r.X + r.Width / 2, r.Y + _inputMargin, r.Width / 2 - _inputMargin * 2, r.Height - _inputMargin * 2);
            sf.Widget.Page = page;
            sf.Widget.BackColor = Color.LightYellow;
            doc.AcroForm.Fields.Add(sf);
            drawField("DATE: ", fields3[1, 2], _Names.SupSignDate);

            // 完毕:
            return doc;
        }

        // 简单的表格绘制方法。返回表格单元格矩形数组。
        private RectangleF[,] DrawTable(PointF loc, float[] widths, float[] heights, GcGraphics g, GCDRAW.Pen p)
        {
            if (widths.Length == 0 || heights.Length == 0)
                throw new Exception("Table must have some columns and rows.");

            RectangleF[,] cells = new RectangleF[widths.Length, heights.Length];

            var r = new RectangleF(loc, new SizeF(widths.Sum(), heights.Sum()));

            // 绘制左边框(第一个除外):
            float x = loc.X;
            for (int i = 0; i < widths.Length; ++i)
            {
                for (int j = 0; j < heights.Length; ++j)
                {
                    cells[i, j].X = x;
                    cells[i, j].Width = widths[i];
                }
                if (i > 0)
                    g.DrawLine(x, r.Top, x, r.Bottom, p);
                x += widths[i];
            }
            // 绘制顶部边框(第一个除外):
            float y = loc.Y;
            for (int j = 0; j < heights.Length; ++j)
            {
                for (int i = 0; i < widths.Length; ++i)
                {
                    cells[i, j].Y = y;
                    cells[i, j].Height = heights[j];
                }
                if (j > 0)
                    g.DrawLine(r.Left, y, r.Right, y, p);
                y += heights[j];
            }
            // 绘制外边框:
            g.DrawRectangle(r, p);
            // 完毕:
            return cells;
        }

        // 使用示例数据填写员工信息和工作时间:
        private Stream FillEmployeeData(GcPdfDocument doc)
        {
            // 出于本示例的目的,我们使用随机数据填写表格:
            var empName = "Jaime Smith";
            SetFieldValue(doc, _Names.EmpName, empName);
            SetFieldValue(doc, _Names.EmpNum, "12345");
            SetFieldValue(doc, _Names.EmpDep, "Research & Development");
            SetFieldValue(doc, _Names.EmpTitle, "Senior Developer");
            SetFieldValue(doc, _Names.EmpStatus, "Full Time");
            var rand = new Random((int)Common.Util.TimeNow().Ticks);
            DateTime workday = Common.Util.TimeNow().AddDays(-15);
            while (workday.DayOfWeek != DayOfWeek.Sunday)
                workday = workday.AddDays(1);
            TimeSpan wkTot = TimeSpan.Zero, wkReg = TimeSpan.Zero, wkOvr = TimeSpan.Zero;
            for (int i = 0; i < 7; ++i)
            {
                // 开始时间:
                var start = new DateTime(workday.Year, workday.Month, workday.Day, rand.Next(6, 12), rand.Next(0, 59), 0);
                SetFieldValue(doc, _Names.DtNames[_Names.Dows[i]][0], start.ToShortDateString());
                SetFieldValue(doc, _Names.DtNames[_Names.Dows[i]][1], start.ToShortTimeString());
                // 时间结束:
                var end = start.AddHours(rand.Next(8, 14)).AddMinutes(rand.Next(0, 59));
                SetFieldValue(doc, _Names.DtNames[_Names.Dows[i]][2], end.ToShortTimeString());
                var tot = end - start;
                var reg = TimeSpan.FromHours((start.DayOfWeek != DayOfWeek.Saturday && start.DayOfWeek != DayOfWeek.Sunday) ? 8 : 0);
                var ovr = tot.Subtract(reg);
                SetFieldValue(doc, _Names.DtNames[_Names.Dows[i]][3], reg.ToString(@"hh\:mm"));
                SetFieldValue(doc, _Names.DtNames[_Names.Dows[i]][4], ovr.ToString(@"hh\:mm"));
                SetFieldValue(doc, _Names.DtNames[_Names.Dows[i]][5], tot.ToString(@"hh\:mm"));
                wkTot += tot;
                wkOvr += ovr;
                wkReg += reg;
                //
                workday = workday.AddDays(1);
            }
            SetFieldValue(doc, _Names.TotalReg, wkReg.TotalHours.ToString("F"));
            SetFieldValue(doc, _Names.TotalOvr, wkOvr.TotalHours.ToString("F"));
            SetFieldValue(doc, _Names.TotalHours, wkTot.TotalHours.ToString("F"));
            SetFieldValue(doc, _Names.EmpSignDate, workday.ToShortDateString());

            // 代表“员工”对文档进行数字签名:
            var pfxPath = Path.Combine("Resources", "Misc", "JohnDoe.pfx");
            var cert = new X509Certificate2(File.ReadAllBytes(pfxPath), "secret",
                X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.PersistKeySet | X509KeyStorageFlags.Exportable);
            var sp = new SignatureProperties()
            {
                SignatureBuilder = new Pkcs7SignatureBuilder()
                {
                    CertificateChain = new X509Certificate2[] { cert }
                },
                DocumentAccessPermissions = AccessPermissions.FormFillingAndAnnotations,
                Reason = "I confirm time sheet is correct.",
                Location = "TimeSheetIncremental sample",
                SignerName = empName,
                SigningDateTime = Common.Util.TimeNow(),
            };

            // 连接签名字段和签名属性:
            SignatureField empSign = doc.AcroForm.Fields.First(f_ => f_.Name == _Names.EmpSign) as SignatureField;
            sp.SignatureField = empSign;
            empSign.Widget.ButtonAppearance.Caption = empName;
            // 某些浏览器 PDF 查看器不显示表单字段,因此我们渲染一个占位符:
            empSign.Widget.Page.Graphics.DrawString("digitally signed", new TextFormat() { FontName = "Segoe UI", FontSize = 9 }, empSign.Widget.Rect);

            // 我们现在“展平”表单:​​循环遍历文档 AcroForm 的字段,
            // 将其当前值绘制到位,然后删除字段。
            // 这将生成一个 PDF,其中文本字段的值作为常规的一部分
            // (不可编辑)内容(我们留下由主管填写的字段):
            FlattenDoc(doc, _Names.EmpSuper, _Names.SupSignDate);

            // 完成后,现在保存带有员工签名的文档:
            var ms = new MemoryStream();
            // 请注意,我们在这里不使用增量更新(第三个参数为 false)
            // 因为这还不需要(但稍后主管签名时将需要/使用):
            doc.Sign(sp, ms, false);
            return ms;
        }

        // 设置具有指定名称的字段的值:
        private void SetFieldValue(GcPdfDocument doc, string name, string value)
        {
            var fld = doc.AcroForm.Fields.First(f_ => f_.Name == name);
            if (fld != null)
                fld.Value = value;
        }
    }
}